IL9 and glioblastoma: To establish HIV latency in vitro, LARA conditions were optimized to mimic the homeostatic T cell environment in lymph nodes, which supports the long-term maintenance of memory CD4+ T cells, including the addition of transforming growth factor β (TGF-β) and IL-7, two cytokines that promote T cell survival and quiescence (29, 66, –, 71), and conditioned medium from the glioblastoma cell line H-80 (72, 73), which also contains cytokines that promote quiescence (TGF-β1, -2, and -3 and IL-9) and survival (IL-21) (Fig. S4a) (74).