Our studies on ATRT revealed the following key findings: (1) RRM2 exhibits elevated expression in ATRT compared with benign tumors or normal brain tissues, (2) increased RRM2 is correlated with poor survival rate among ATRT patients, (3) depletion of RRM2 inhibits ATRT cell growth, triggers DNA damage, and induces cell death, (4) the RRM2 inhibitor, COH29 suppresses tumor growth and prolongs survival in mice. Here, RRM2 is linked to neoplasm.