PRF1 and systemic lupus erythematosus: In CD56dimCD57− NK cells, there were differences in percentage of CD107a (49.9 ± 13.7%, n = 4 versus 22.5 ± 4.30%, n = 4, P < 0.05), perforin (92.2 ± 6.50%, n = 10 versus 69.1 ± 20.1%, n = 24, P < 0.05), granzyme B (90.0 ± 4.69%, n = 6 versus 65.3 ± 22.6%, n = 9, P < 0.05) and CD16 (93.7 ± 4.30%, n = 12 versus 75.2 ± 16.8%, n = 17, P < 0.05) between HCs and SLE patients, but no differences in expressions of NKG2D and NKG2A (Fig. 5A, B).