Our findings from in vitro cell culture assays and an in vivo xenograft model suggest that phosphorylation of TFCP2L1 by cyclin‐dependent kinase 1 (CDK1) represents a novel molecular circuitry for pluripotency in ESCs and also contributes to proliferation, self‐renewal, and invasion of BC cells. This evidence concerns the gene TFCP2L1 and breast cancer.