Whole-cell voltage-clamp analysis of predominant ANO2 isoforms containing or lacking exon 4–encoded sequence. (A) Whole-cell currents from a HEK293T cell expressing the olfactory ANO2 Isoform B obtained with a pipette solution containing 1.5 µM Ca²⁺. (B) Negligible currents from a cell expressing the B_Δ4 ANO2 isoform. (C) Mean I-V relation from cells expressing either Isoform B or Isoform B_Δ4 and untransfected cells (n = 10 for each condition; error bars are ±SEM). Current amplitudes were measured at the end of the voltage-step protocol shown above A. *, currents from Isoform B were significantly different from untransfected control (P < 0.0001; two-way ANOVA). ns, nonsignificant difference between Isoform B_Δ4 and untransfected control (P > 0.5; two-way ANOVA).