The R65Q mutation does not affect the subcellular localization of Munc18-2. CTLs from a control or P1 were incubated for 15 minutes at 37°C on polylysine-coated coverslips. Cells were fixed, permeabilized, and stained using mouse anti-granzyme-A or rabbit anti-Munc18-2 antibody. Large arrowheads show the intracellular pool of Munc18-2. Smaller arrows show the fraction of Munc18-2 localizing at the plasma membrane. Insets display a zoomed-in view of the selected area. Bars represent 5 μm.