Biophysical and pharmacological characterization of Kv1.3 and KCa3.1 channels in CEM-CAR cells. (A) Whole-cell current trace recorded in CD19-CAR expressing CEM cell using 200-ms-long voltage-ramp protocol ranging from -120 mV up to +50 mV, holding potential was −70 mV (see Materials and methods). (B) Current traces were registered in the absence (black line) and presence of 1 nM Vm24 (red line) in aspartate bath solution using ramp protocol described in panel A. Green line is the difference of the black and red records exhibiting the Kv1.3 whole-cell current. (C) Current traces were recorded in normal extracellular solution (black line), then in high K⁺ solution (blue line) and finally in the presence of 200 nM TRAM34 dissolved in high K⁺ solution (orange line). The same voltage ramp protocol was used as in A and B.