GPR68 and breast cancer: Although our studies indicate OGR1 as the major acid sensor in MCF7 and T47D cells that drive acid-induced LD accumulation, it is possible that acid-sensing ion channels (ASICs) or other GPCRs such as TDAG8 could contribute to acid sensing in other breast cancer cell lines, supporting the notion that lipogenic phenotype is an atavistic response to microenvironmental stress induced by acidosis.