In Vitro: α-Cyano-4-hydroxycinnamic acid (α-Cyano-4-hydroxycinnamate) inhibits monocarboxylates transport such as lactate and pyruvate. α-Cyano-4-hydroxycinnamic acid (CHC; 0.5 mM and 1 mM) of 1 mM has a significant inhibitory effect on branching morphogenesis and decreases the epithelial perimeter and area of lung explants in a dose dependent way. At 100 μM concentration, α-Cyano-4-hydroxycinnamic acid rapidly and almost totally inhibits O2 uptake by rat heart mitochondria oxidizing pyruvate. Inhibition can be detected at concentrations of inhibitor as low as 1 μM although inhibition took time to develop at this concentration. Inhibition can be reversed by diluting out the inhibitor.