GPR68 and cancer: Several studies have investigated OGR1 in cancer, specifically in pancreatic, breast, ovarian, skin, liver, head and neck, colorectal and oesophageal cancer [5, 6, 14, 18, 30, 33, 48, 54, 63, 77, 78, 88, 96, 98, 101], ranging from pure expression (e.g. [5, 48]) to functional studies in cells (e.g. [77, 96, 98]) and/or mice (e.g. [6, 54, 98]).