PTEN and malignant colon neoplasm: Further validation by RT-PCR with divergent primers revealed that hsa_circ_0002232 and hsa_circ_0019060 were more highly expressed in the normal human colonic epithelial cell line NCM460 and colon cancer cell lines DLD1, LoVo and HCT116 relative to other circRNAs derived from PTEN (Fig. 1A).