MCT1/4-mediated lactate secretion from cancer cells plays an important role in mediating macrophage polarization to the M2-like state, which presents with immunosuppressive properties (Colegio et al., 2014; Ohashi et al., 2017; Mu et al., 2018; Liu et al., 2019; Stone et al., 2019). Here, SLC16A1 is linked to cancer.