CD28 and metabolic dysfunction-associated steatotic liver disease: Focusing on the significantly reduced CD4+ T cells in MASLD model mice (Figure 4), subpopulation profiling classified them into CD4 memory T cells (Ifng, Il12rb2, Nkg7), activated CD4+ T cells (Cd28, Gpr183, S100a4), naive CD4+ T cells (Lef1, Sell, Ccr7) and Tregs (Foxp3, Il2ra, Ctla4, Figure 4A,B).