HS-173 is a potent and selective inhibitor of PI3Kα (phosphoinositide 3-kinase alpha), a key enzyme in the PI3K/AKT/mTOR signaling pathway, which is frequently dysregulated in various cancers. It is primarily used in research settings to study oncogenic signaling pathways and to evaluate the therapeutic potential of PI3K inhibition. Due to its high selectivity and strong anti-proliferative activity, HS-173 has shown promise in preclinical studies for the treatment of cancers with PIK3CA mutations, including breast, ovarian, and colorectal cancers. It is also employed as a tool compound in cellular and biochemical assays to dissect pathway dynamics and to support the development of targeted cancer therapies. Its application extends to combination therapy studies, where it is tested alongside other anticancer agents to overcome resistance and enhance efficacy.