The results showed that our quantitative FCIA had higher sensitivity when using single anti-P-selectin antibody (43.90% vs. 21.95%) or 5 antibodies combined (68.29% vs. 41.46%) and comparable specificity (84.93% vs. 90.41%) and accuracy (78.95% vs. 72.81%) for ITP diagnosis (Table 5). The gene discussed is SELP; the disease is autoimmune thrombocytopenic purpura.