To better characterize the effects of HIV-1 gp120 proteins on astrocytoma function, we examined chemotaxis induced in microglia by U87-MG cells treated with HIV-1 gp120 proteins and HIV-1 gp120 proteins alone to test if HIV-1 gp120 proteins alone and/or the cytokines released by the astrocytoma cells may recruit microglia to HIV-1 gp120 sites. Here, ITIH4 is linked to astrocytoma (excluding glioblastoma).