CA9 and cancer: While SLC16A3 (MCT4), SLC2A1 (GLUT1) and CA9 have been reported in metabolic reprogramming of malignant cells [37], the others have been shown to support tumor progression and chemoresistance via maintaining cancer stemness, epithelial-mesenchymal transition: CEACAM5, CD24 [38,39] or via driving proliferation: TMEM45A [40], EGFR [41].