Further evidence of this is that MCT4, which exports lactate, is present in cancer associated fibroblasts and is up regulated by oxidative stress, and cancer cell MCT1 is up regulated when co-cultured with fibroblasts (Whitaker-Menezes et al., 2011; Fu et al., 2017; Koukourakis et al., 2017; Wilde et al., 2017). Here, SLC16A1 is linked to cancer.