MTX-531(NSC827271) is a first-in-class, potent and selective inhibitor of EGFR and PI3Kα with an IC50 of 14.7 nM and 6.4 nM, respectively. It may play a role in treating Head and Neck Squamous Cell Carcinoma (HSNCC), squamous lung cancers, and certain EGFR/PI3K-driven triple-negative breast cancers.