CDKN1B and neuroblastoma: Because somatic mutations of the CDKN1B gene are rare in human malignancies 17, 18 and the reduced protein and gene expression of CDKN1B is frequently observed in neuroblastoma 21, 22, it has been suggested that common genetic variants in CDKN1B may be associated with reduced mRNA and protein expression and increased risk of neuroblastoma.