CIP2A and colorectal cancer: CIP2A protein levels were very low in human epidermal keratinocytes, nontumorigenic mouse embryo fibroblasts, and immortalized NIH3T3 mouse fibroblasts, but CIP2A was overexpressed in HeLa cells, HT-1080 fibrosarcoma cells, head and neck squamous cell carcinoma and colorectal cancer.