The expression levels of CD69 on T cells fluctuated during anti-TB chemotherapy (Portales-Pérez et al., 2002) and in HIV-1/TB co-infected patients, the percentage of CD4+ T cells expressing CD69+ was related to TST and IGRA results (Hsieh et al., 2000) confirming an association with disease status. The gene discussed is CD4; the disease is tuberculosis.