ESR1 and colorectal carcinoma: The best studied truncated ER has been ERα36 (36 kDa) in breast and gastric cancers [163,164], which transduces estrogenic nongenomic signalling to promote cell proliferation and metastatic potential [165] Apart from one study reporting decreased ERα36 mRNA expression with advanced Stage CRC [166], the relevance of truncated ERs to oestrogen signalling and sex differences in CRC is unknown and merits further investigation.