PRF1 and systemic lupus erythematosus: Compared with CD56dimCD57+ NK cells in HCs, CD56dimCD57+ NK cells in SLE patients showed decreased expressions of perforin (97.5 ± 3.01%, n = 10 versus 82.2 ± 15.1%, n = 24, P < 0.01), granzyme B (97.3 ± 4.47%, n = 6 versus 72.5 ± 23.6%, n = 9, P < 0.05), CD16 (97.7 ± 3.01%, n = 12 versus 79.3 ± 17.5%, n = 17, P < 0.01) and NKG2D (97.5 ± 2.65%, n = 10 versus 92.5 ± 5.90%, n = 10, P < 0.05), along with increased NKG2A expression (8.54 ± 7.20%, n = 7 versus 26.7 ± 17.3%, n = 11, P < 0.05) (Fig. 5A, B).