KLF4 and colorectal carcinoma: ciRS-7 (Circular RNA Sponge For MiR-7, also called Cerebellar Degeneration Related 1 antisense, CDR1as; the current name of CDR1as according to the HUGO gene nomenclature committee is long intergenic non-protein coding RNA 632, LINC00632) has been described as a tumor promoter in CRC and esophageal squamous cell carcinoma and affects KLF4 expression in hepatocellular carcinoma (HCC) [31,35,36].