FOLR1 and malignant colon neoplasm: Although we have not completely finished the delineation of the signaling pathways involved in regulating FA-induced growth inhibitions in HT-29 and LoVo colon cancer cell lines, our preliminary data showed that FRα is the only isoform detected in HT-29 and LoVo and c-SRC as well as ERK were activated and the levels of TP53, CDKN1A and CDKN1B protein were increased in the FA-treated HT-29 and LoVo.