The pooled RRs for neutropenia, anemia, thrombocytopenia, lymphopenia, pneumonia, diarrhea, and fatigue in the MAbs targeting CD38 group vs control group were 1.40 (95%CI 1.17–1.67), 0.82 (95%CI 0.66–1.01), 1.15 (95%CI 0.92–1.43), 1.70 (95%CI 1.26–2.29), 1.51 (95%CI 1.21–1.89), 1.33 (95%CI 0.92–1.91), and 2.00 (95%CI 1.33–3.02) (Fig. 6a, b). This evidence concerns the gene CD38 and lymphopenia.