CDKN2A and colonic neoplasm: To study whether the above CBX7 expression-dependent effect of P14AS on the upregulation of P14ARF, P15INK4B, P16INK4A expression occurs in human tissues, we determined the levels of P14ARF, P15INK4B, P16INK4A, P14AS and CBX7 in colon cancer and paired normal surgical margin tissues from patients (n = 75) by qRT-PCR.