HLH onset occurs later in patients with syntaxin-11 deficiency than in patients with RAB27A- and PRF1^−/− deficiencies. (A) Cumulative incidence and (B) age at onset of HLH in FHL2 (PRF1 deficiency, gray circles; n = 72), GS2 (RAB27A deficiency, gray triangles; n = 61), and FHL4 (STX11 deficiency, open squares; n = 30) patients carrying null biallelic mutations, as detailed in supplemental Table 1. The incidence of HLH was analyzed with a log-rank test. *P < .05 for FHL4 versus GS2 patients. ***P < .001 for FHL2 versus GS2 and FHL2 versus FHL4. The onset of HLH was analyzed with a 1-way ANOVA. **P < .01. ***P < .001.