Comparison of eucalyptol sensitivities of TRPM8 channel species orthologues (human, mouse and rat) and determination of sensitivity of human TRPM8 channels to a eucalyptol metabolite, measured by Ca2+ fluorimetry in HEK293T cells. (A) Concentration response analysis of eucalyptol activation of human TRPM8 channels,with EC50 values as shown. (B) Concentration–response relationship of human TRPM8 channel activation by 2‐hydroxy‐1,8‐cineol. (C) Dose–response relationship of eucalyptol activation of human, mouse and rat TRPM8. The estimated EC50,values are shown in the Figure.