条件性感染和肿瘤主要发生于皮肤及邻近的粘膜表面已成为AIDS的特征性表现.HIV-1感染者中,它们的发病大多是由于HIV-1诱导的免疫系统CD4~+细胞数减少,该细胞的减少引起严重的免疫缺陷.但又发现某特定细胞感染HIV-1后并不一定死亡,而有可能改变其基因表达类型.这样最终使该感染细胞发生生长和(或)功能的异常,随之在同一微环境或远隔部位的其它细胞也出现类似的异常. Conditioned infections and tumors mainly occur on the skin and adjacent mucosal surfaces have become characteristic manifestations of AIDS. Among HIV-1 infected individuals, their incidence is mostly due to HIV-1 induced reduction in the number of immune system CD4~+ cells. The reduction of cells causes serious immunodeficiency. However, it is found that a particular cell infected with HIV-1 does not necessarily die, but may change its gene expression pattern. This ultimately causes abnormalities in the growth and/or function of the infected cell. A similar abnormality also occurs in other cells in the same microenvironment or distant sites.