GADD45A and malignant colon neoplasm: Forty-nine of these 61 genes have already been described in human PBMCs [17, 20, 24, 25], THP-1 cells [26] or in other cellular systems, such as GADD45A in the context of prostate and colon cancer cells [30, 31], to respond significantly to 1,25(OH)2D3.