HIF1A and colorectal carcinoma: In a normoxic environment, EZH2 is guided to the promoter region of HIF-1α by the long non-coding RNA (lncRNA) HITT (HIF-1α inhibitor at translation levels) and suppresses its transcription by forming an RNA/PRC2/DNA triplex, while EZH2 is untethered due to HITT degradation under hypoxia, which hinders the repressive action of EZH2 on HIF-1α transcription in CRC cells [33].