Kamyab K, et al. - To find some consistent histological clues for distinguishing alopecia areata (AA) and androgenic alopecia (AGA), researchers assessed the characteristics of inflammatory cell infiltration using CD3, CD4, CD8, and CD20 antigens, in these two entities. In IHC samples, characterization of CD3 and CD8 was helpful, especially when in more than 50% of the infiltrated cells, the density of CD3 and CD8 T cells are significant and these infiltrated were located intrafolliculary. Furthermore, CD3 was the most specific and sensitive test for differentiating of AA from AGA.