Typically, MCP-1 (lactate importer) is more commonly expressed under physiological conditions, while cancer cells upregulate the MCP-4 (lactate exporter), as a consequence of HIF1-α activation, to overcome intracellular dysregulations triggered by a build-up of lactate (Li et al., 2022a; Parks et al., 2011; Halestrap, 2013), (Lock et al., 2013; Becker, 2020; Ratner, 1990; Chouaib et al., 2017; Chen et al., 2023), (Li et al., 2022a; Parks et al., 2011; Halestrap, 2013). The gene discussed is HIF1A; the disease is cancer.