CD4 and infection: Consistent with the significantly impaired HIV-1 entry and infection promoted by LTNP-ECs’ Envs and their low CD4 binding (Fig. 2B and 3E, respectively), the Envs from LTNP-ECs promoted acetylation of α-tubulin to a smaller extent than the Env from the BaL.01 viral strain (Fig. 5A).