VB124 is an orally active, potent, and selective MCT4 inhibitor, demonstrating specificity in hindering lactate efflux, with IC50 values of 8.6 nM and 19 nM for lactate import and export, respectively, in MDA-MB-231 cells. Its high selectivity for MCT4 over MCT1 positions VB124 as a promising agent for researching cardiac hypertrophy, heart failure, and metabolic disorders [1].