Secondly, Brown et al. reported that lactate activates G protein-coupled receptor 81 (GPR81, also known as hydroxycarboxylic acid receptor 1 or HCAR1) in DCs, which inhibits cell-surface presentation of MHCII, exerts a paracrine effect and prevents the presentation of tumor-specific antigens to other immune cells (Brown and Ganapathy, 2020). The gene discussed is HCAR1; the disease is neoplasm.