PCNA and colorectal carcinoma: The protein levels of PCNA and MMP9 decreased, while the expression level of the apoptosis marker cleaved caspase-3 increased in cells transfected with si-LncRNA-RP11-197K6.1; this finding indicated that the downregulation of lncRNA RP11-197K6.1 inhibited the proliferation and invasion abilities of CRC cells while promoting their apoptosis.