CD27 and HIV-1 infection: We initiated the study by assessing the frequency and changes induced by HIV-1 infection in Naive CD19+CD10−CD21+CD27−, Activated Memory (AM) CD19+CD10−CD21−CD27+, Resting Memory (RM) CD19+CD10−CD21+CD27+ and Tissue Like Memory (TLM) CD19+CD10−CD21−CD27− B cell subsets in the three groups studied (controls, HIV-1 non-treated and HIV-1 treated) independently of age (Additional file 1: Figure S1 and Additional file 2: Figure S2).