PRF1 and myeloid sarcoma: In MS patients, EDSS score before treatment was correlated with the frequency of MOG-specific CD8+ TCM (r = 0.421, P = 0.041); granzyme B expression in CD8+ TCM (r = 0.507, P = 0.012); and, for CD8+ TEM, the expression of granzyme B (r = 0.512, P = 0.01), perforin (r = 0.446, P = 0.029), and PD-1 (r = −0.520, P = 0.009).