CDKN2A and cancer: In contrast, HPV-driven tumors degrade p53, increase p16 expression, and inactivate Rb.6 Moreover, HPV− cancers commonly present with a loss of chromosome 9p, which is responsible for downregulation of p16 (CDKN2A) expression, and also duplication of chromosome 7p, promoting epidermal growth factor receptor (EGFR) overexpression.