PCAT1 and colorectal carcinoma: To next determine whether there is direct regulation, we performed ChIP-PCR in Oxa-resistant CRC cells and observed binding of endogenous KLF4 protein to the PiHL promoter KLF4 binding site (−54 to −274) but not to upstream (−751 to −953) nor exon 2 (+316 to +464) (Fig. 2G).