exSSI between ion binding sites quantifies the degree of cooperativity in the knock-on mechanism of cation permeation in TRPV channels. The mean exSSI and SEM between transitions from binding sites A and B (left) and binding sites B and C (right) are shown for Ca²⁺ (orange) and Na⁺ (blue) cations in monocationic solutions. For each exSSI, the mean maximum exSSI_max and standard error are also shown (gray), and the exSSI_norm is reported in Table S5.