CD38 and synovial sarcoma: CD38 on IgD+ CD38+ B cell (OR = 0.861, 95%CI 0.781–0.949, p = 0.003, PFDR = 0.028) reduced the risk of SS, and the results of the other four methods were similar: MR-Egger (OR = 0.833, 95%CI 0.707–0.981, p = 0.045), weighted median (OR = 0.867, 95%CI 0.754–0.998, p = 0.046), simple mode (OR = 0.789, 95%CI 0.633–0.983, p = 0.051), and weighted mode (OR = 0.859, 95%CI 0.748–0.987, p = 0.048) (Table 1).