CD38 and breast cancer: In B cell group, Unswmem AC (P = 0.015, OR = 0.950, 95%CI = 0.911~0.990), CD24+CD27+AC (P = 0.011, OR = 0.968, 95%CI = 0.944~0.992), IgD+CD38dim%lymphocyte (P = 0.041, OR = 0.971, 95%CI = 0.944~0.998) had a negative causal relationship with breast cancer, CD38 on IgD-CD38dim (P = 0.028, OR = 1.022, 95%CI = 1.002~1.042), IgD-CD38dim%B cell (P = 0.002, OR = 1.060, 95%CI = 1.020~1.102) and IgD on IgD+CD38-unswmem (P = 0.011, OR = 0.945, 95%CI = 0.904~0.987) were positively correlated with breast cancer.