Abstract: The invention relates to a class of small molecule inhibitors of GPR68/OGR1, a proton-sensing/stretch-sensing/sheer-stress-sending G-protein coupled receptor, and related receptors GPR4 and GPR65. These inhibitors are useful as a therapeutic for glioblastoma and other neoplasms, as a monotherapy or adjuvant, and also can be used as a treatment for other conditions, such as osteoporosis, inflammatory bowel disease, autoimmune and chronic inflammatory diseases such as multiple sclerosis and inflammatory pain syndromes, GERD, aspiration pneumonitis, bacterial and viral pneumonia, COPD, acute respiratory distress syndrome (ARDS), and COVID-19.