Throughout the book, she refers to herself as "the side effect," which is just totally correct. Cancer kids are essentially side effects of the relentless mutation that made the diversity of life on earth possible.

“Non puoi scegliere di essere ferito in questo mondo, vecchio mio, ma hai qualch…”

“Hazel Grace. No. I will grant you that you did spend my one and only Wish, but …”

“Of course I tensed up when he touched me. To be with him was to hurt him-inevit…”

“My heart is broken," Tiny says, as if the thing has never happened before to hi…”