CCND1 and colorectal carcinoma: Interestingly, the effect of Schlafens on colon cancer extends beyond the human Schlafens, as exogenous expression of mouse Slfn3 in human CRC cell lines that lack Slfn3 induces G0/G1 arrest by downregulating Cyclin D1 expression and reducing phosphorylation of retinoblastoma (pRB) protein [45].