Intestinal mast cell increase in CF mice and reversal by simultaneous inactivation of Kcnn4. (A) Representative Peyer’s patches of each genotype, and (B) corresponding perimeter measurements. Figures represent individual animals and red lines means ± S.E.M. Mann-Whitney test: *indicates p = 0.016, **p = 0.008 and ns, non-significant difference; n = 5 for each group. (C) Toluidine blue staining of small intestine used to detect and quantify mast cells (red arrows). See Table 2 for values and statistics. (D) Proliferative response of mast cells in response to SCF is summarized. Values are given as mean ± S.E.M. n = 5. Paired Student’s t test: *indicates p < 0.05 compared to the corresponding control. Mast cell chemotactic response to DNP and TRAM-34 effects are summarized in (E). Values are given as means ± S.E.M. Paired Student’s t test: *indicates p < 0.05 compared to the respective control. #Indicates p < 0.05 compared to DNP effect, n = 6 for each genotype.