CD4 and Insulin resistance: The abnormal differentiation of CD4+ Th cell subpopulations may impair β-cell function, aggravate insulin resistance, and contribute to the development of T2D through producing cytokines and participating in chronic and low-grade inflammation (Aydin et al., 2023; Drenthen et al., 2024; Han et al., 2024; Valentine and Nikolajczyk, 2024).