We detected IgM+IgD+ and significant overexpression of IL-10 on total CD19+CD20+ B cells and on CD19+CD20+CD5+CD1d+ Breg cells and a significant overexpression of IL-10 and IgM on CD19+CD20+CD27+IgD+ NSw MBCs in the blood of patients with MASLD. The gene discussed is CD19; the disease is metabolic dysfunction-associated steatotic liver disease.