GPR35 and neoplasm: Recently, a constitutive ligand-independent pro-cancer function of GPR35 was reported, demonstrating that GPR35 interacted with Na+/K+-ATPase inducing colorectal cancer (CRC) cell proliferation and glycolysis (Schneditz et al., 2019), also driving macrophages to promote angiogenesis in the tumor microenvironment (Pagano et al., 2021).