Both CD4+ and CD8+ subsets of T-cells were more frequent in malignant PC compared to BPH (PD1+CD4+ T-cells: median 73.0% vs. 32.7%, p < 0.001) (Figure 4B) (PD1+CD8+ T-cells: median 69.2% vs. 36.1%, p = 0.001) (Figure 4C). Here, CD4 is linked to pachyonychia congenita.