CDKN1A and colonic neoplasm: Studies with various cancer lines including colon cancer HCT116 p21 wild-type and p21-knockout (p53 wild-type), as well as cervical carcinoma HeLa (p53 inactive) and osteosarcoma Saos-2 (p53 deficient) cell lines treated with sip21 #1, demonstrated that depletion of p21 causes mitotic defects independent of its p53 status [27].