Furthermore, studies in C57BL/6 mice showed that CD4+ T cells, largely Type 1 T helper cells (Th1)/T follicular helper cells (Tfh) subtypes, play a protective role, with the T-box transcription factor TBX21 (T-bet), Cluster of Differentiation 40 (CD40), Cluster of Differentiation 40 Ligand (CD40L), and MCH II pathways crucial in mediating defense against RVFV encephalitis [42]. The gene discussed is CD4; the disease is encephalitis.