Stravodimou A, et al. - Tumor infiltrating lymphocyte (TIL) subpopulations and precursors were assessed in cases of invasive squamous cell carcinoma (inSCC) by drawing a comparison between two semi-quantitative scoring systems. The presence of regulatory T-cells (Tregs) in these lesions was also evaluated. In cutaneous squamous cell carcinogenesis, T-cells and cytotoxic T-cells progressively increased, whereas Treg counts diminished in inSCC. The K-M score was shown to be an appropriate, easily applicable TIL scoring system in cutaneous inSCC.