Classification of altered genes in LT from HIV-1-infected patients into disease stages and representative hierarchical clustering reveals stage-specific gene signatures. Genes with altered expression (≥1.7 times the level at uninfected baseline, p < 0.05) at the three stages of HIV-1 infection were characterized as the following: unique to the acute stage (S1), asymptomatic stage (S2), or AIDS stage (S3); C1, common to all stages; C2, common to acute and asymptomatic stages; C3, common to asymptomatic and AIDS stages; and C4, common to acute and AIDS stages. A, Hierarchical cluster analysis of altered genes from HIV-1-infected subjects (stage indicated at the bottom). Green, red, and black areas indicate, respectively, decreased, increased, and no significant change in expression compared with uninfected controls. B, Venn diagram depicting the number of genes with altered expression. The size of each region is proportional to the number of altered genes. Green and red numbers indicate, respectively, decreased and increased expression.