Nearly five years after battling Ewing’s sarcoma, 14-year-old Jake Kleppen had one goal in mind: to be declared a “survivor.” But just months before he was officially in remission, he was diagnosed with treatment-induced leukemia. “Before this Jake had no symptoms, he was a normal 8-year-old kid, and from one day to the next, my world got flipped upside down, and I became a cancer parent, and he became a cancer patient,” says his mother, Marisel Jarrin, 49, an elementary school teacher who lives in Pembroke Pines, Fla. “You think, ‘It can’t happen to me,’ but it can absolutely happen to you — and sometimes twice.” Now, mother and son share their story with PEOPLE‘s Wendy Kantor Grossman.

Marisel Jarrin was driving her two sons, Jake Kleppen, 8, and Justin Kleppen, 7, to the pediatrician for their annual checkups in September 2019.

“It was Friday the 13th, a full moon, all the elements of eeriness were there,” says his mother, Marisel Jarrin, 49, an elementary school teacher who lives in Pembroke Pines, Fla. “The boys are like, ‘Mom, today something bad is gonna happen.’ I vividly remember looking at them and saying, “That’s just superstition, everything’s gonna be fine.”

At the routine appointment, the pediatrician said she didn’t like the way Jake’s left eye looked. It was bulging a little, Marisel recalls. The doctor told Marisel to take him straight to the emergency room.

“I thought that was a bit dramatic,” Marisel says. “But she is an angel on earth.”

After a CT scan, the ER doctor told Marisel he wanted to transfer Jake to another hospital that specializes in eyes. “At this point, I’m still not thinking ‘cancer’ — I thought just really bad sinus buildup,” Marisel says. At Bascom Palmer Eye Institute in Miami, “a ton of specialists came into the room and looked into his eye,” she says, “it was a revolving door of doctors.”

There, doctors discovered a mass between Jake’s sinuses and the muscles that support his eye. They did a biopsy. “We met with an oncologist and he said, ‘I’m almost certain this is cancer,’ ” Marisel recalls.

Days later, the third grader was diagnosed with stage 3 Ewing’s sarcoma behind his eye. The rare cancer usually forms in bone or soft tissue in the limbs or ribs.

Doctors said that because of the location and aggressive nature of the cancer, surgery was not an option. They wanted Jake to begin chemotherapy immediately.

“I would have had a higher chance of dying if they had operated,” says Jake, now 15. “As much as my mom hates to think about death, we have to acknowledge it.”

He had 11 months of chemo before going to Miami Cancer Institute for 31 days of proton beam radiation from December 2019 to February 2020.

“I was more concerned about my hair loss than the actual disease,” Jake admits. But, he got through it — with his brother and sister, Mia, who was 2 at the time, by his side. His siblings visited a lot, “going to the playroom and doing arts and crafts and jumping on the hospital beds,” says Marisel. “They were doing kid stuff. That really kept Jake’s mind occupied.” Once COVID started, they could no longer visit him, so they FaceTimed and sent care packages.

Finally, Jake’s treatment was over. He rang the bell in June 2020.

Over time, Jake’s hair grew back. He started feeling like a normal kid. After five years cancer-free, he would be considered a cancer “survivor.”

But just months before his five-year mark, in January 2025, Jake started feeling off. He was on a week-long winter encampment with the Civil Air Patrol, a nonprofit for youth who are interested in pursuing the Air Force as a career. His dad was there, too: “Jake’s dad is a Marine, and his father’s side of the family has a heavy military history,” Marisel says.

His father, Jay Kleppen, a 51-year-old fire inspector, told Marisel that their son had a rash on his legs but assumed it was poison ivy or something he had picked up in the woods.

But Jake was also exhausted and seemed to be fighting a cold. His parents thought it was because the cadets were waking at 5 a.m. and working hard all day.

When Jake returned home, instead of giving his mom his usual hug and kiss, he walked straight to his bed. Marisel knew something was wrong. She gave him Advil and Gatorade and said if he wasn’t feeling well in the morning, they would go to urgent care.

He woke in a puddle of sweat. “His bed was completely saturated,” his mom said.

At urgent care he tested positive for both flu and strep. They were sent to the ER where further tests showed disturbing results — he had no white blood cells. None.

He was transported via ambulance to Holtz Children’s Hospital. There, it was determined the 14-year-old had contracted a myriad of viruses all at once. “Because he had no white blood cells to fight it, he picked up every virus you can imagine,” his mother says.

Jake was diagnosed with B-Cell acute lymphoblastic leukemia.