Moreover, the altered memory B cell subset distribution was correlated with changes in the frequencies of ICOS+cTfh and IL-21+ICOS+cTfh cells during AHI, suggesting that the memory B cell subset profile changes could be a result of cTfh cells overactivation mediated by pathway of ICOS signaling at the early stages of HIV-1 infection. The gene discussed is IL21; the disease is HIV-1 infection.