Among mediators with complementary effects greater than 15%, elevated IL-18 levels mediated the protective effects of increased FSC-A on CD8+ T cells (Proportion = 28.02%, 95% CI: 25.04–30.98) and CD27 on CD24+ CD27+ B cells (Proportion = 15.03%, 95% CI: 12.71–17.45) against OM. The gene discussed is CD8A; the disease is ocular melanoma.