Pico145 (Compound 31, C31) is a remarkable small-molecule inhibitor of TRPC1/4/5 channels, inhibits (−)-englerin A-activated TRPC4/TRPC5 channels, with IC50s of 0.349 and 1.3 nM in cells; Pico145 shows no effect on TRPC3, TRPC6, TRPV1, TRPV4, TRPA1, TRPM2, TRPM8. Pico145 also inhibits human TRPC4-TRPC1 and TRPC5-TRPC1 concatemers expressed in HEK 293 Tet cells (IC50, 0.03 nM and 0.2 nM, respectively). The potency of Pico145 can be reduced by increased (−)-englerin A concentration. Furthermore, Pico145 potently inhibits RPC4-TRPC1 channels activated by sphingosine 1-phosphate (S1P), and suppresses S1P-evoked Ca entry through TRPC4-TRPC1 channels with an IC50 of 0.011 nM. Pico145 also sensitizes EA-sensitive cancer cell line (Hs578T cells) (IC50, 0.11 nM). Pico145 (100 nM) lacks effect on store-operated Ca entry and histamine-evoked Ca entry into endothelial cells.