In the absence of ML382, the IC50 for BAM8-22 inhibition of ICa is 0.66 ± 0.05 μM. In the presence of 0.1 μM, 1 μM, 10 μM, and 30 μM ML382, BAM8-22 IC50 is reduced to 0.43 ± 0.02 μM, 0.25 ± 0.02 μM, 0.06 ± 0.01 μM, and 0.08 ± 0.01 μM, respectively. A lower IC50 generally indicates a higher potency; thus, ML382 dose-dependently increases the potency of BAM8–22, further demonstrating that ML382 is a positive allosteric modulator of MRGPRX1.