CDK4 and colorectal carcinoma: Intriguingly, hsa_circ_0001955 expression was positively correlated with expression of CDK4, MMP12 and RAB3IP, and hsa_circ_0000977 was also positively associated with expression of FOXO1, MBNL1, MEF2C, RECK, PPM1E, TTLL7 and PCP4L1 in CRC.