K4750Q mutation-driven kinetic alterations in luminal Ca²⁺ activated channels. (A) Dwell time distributions (pCa_lum 4) from WT and K4750Q. (B) State models of WT and K4750Q. (left) WT: maximum likelihood value (LL) = 9,802, events = 2,133; (right) K4750Q: LL = 7,083, events = 3,886. (C) Model-based simulated traces from WT and K4750Q. n = 6 for WT and mutant channels.