>> kaden erickson: yes. it made me feel a little bit normal, more normal than i've been for a while. >> whitaker: feeling normal didn't last long. shortly after returning home, kaden learned his cancer had returned for the third time. as we settled in for our interview, his mom jeanne adjusted the medication he needs. it's pumped into his body next to his heart. you're in quite a struggle with this disease. >> kaden erickson: there are some bad things in my body that are kind of stubborn. >> whitaker: i think you're kind of stubborn yourself. >> kaden erickson: thank you... i think. >> whitaker: kaden is so stubborn that, after deliberating for a week, he decided to undergo a third agonizing bone marrow transplant. the previous two were so difficult, his parents didn't want to force him to go through it again. how did you make that decision? >> kaden erickson: would i rather just die or would i have it was a tough decision to make. >> whitaker: because the therapy makes you feel bad? >> kaden erickson: it can