CDKN2C and neoplasm: Interestingly, genes encoding CDK inhibitors, such as CDKN1A (p21Cip1), CDKN2A (p16INK4A), CDKN2C (p18INK4C) were downregulated in our CNFPA, which is consistent with a cyclin-mediated oncogenic mechanism, whereby these proteins act as tumor suppressors.