In another study, obesity was associated with a decreased number of activated CD8+ T cells expressing CD28, CD40 ligand (CD40L), IFNγ as well as both IFNγ and GrB, and both CD28 and interleukin 12 receptor (IL12R) [42]. The gene discussed is GZMB; the disease is obesity due to melanocortin 4 receptor deficiency.