CDKN2A and neuroblastoma: Notably, the nonsynonymous rare germline alleles (minor allele frequencies ranging between 0.01% and 5%) in ALDH18A1 [23], CDKN2A [24], TGFBR3 [25], and ALDH1B1 genes had predicted unfavorable effects on protein function and were previously associated with NB, indicating a possible role for an underlying oligogenic mechanism [26].