GSK 2833503A is a potent and selective TRPC6 and TRPC3 antagonist (IC50 = 3-16 nM and 21-100 nM, respectively). GSK 2833503A exhibits >63-fold selectivity over other ion channels, including other TRP channels, CaV1.2, hERG and NaV1.5. GSK 2833503A suppresses angiotensin II or endothelin-1-induced cardiac hypertrophy signaling in HEK293 cellsin vitroand in cardiomyocytes.