Our results showed that the average percentage of CD155-positive cells in PC tissues and adjacent tissues was 92.64% (range, 40%-95%) and 39.52% (range, 0%-90%) respectively; the staining intensity score for CD155 was close to 3 in PC tissues and 1-3 in the adjacent tissues (Figure 2A-2F). Here, PVR is linked to pachyonychia congenita.