Macrophages act as an factory for Human Immuno- deficiency Virus (HIV) during infection. When this virus infects the body of the person, it is these macrophages where replication of the virus takes place. The RNA genome of the virus replicates to form viral DNA which then gets incorporated into the host's cell DNA. Here, these virus particles continuously replicates to form new virus and hence these macrophages survive for long to carry out the process of replication.