RIPK2 and pachyonychia congenita: Considering the multiple kinase activity of RIPK2, and that its high expression in PC predicts a poor prognosis in TCGA database, we next corroborated the expression of RIPK2 at the protein level by immunohistochemistry in the Human protein atlas database (Fig. 2D), and at the mRNA level in independent datasets GSE46234 and GSE62165 (Fig. 2E–G).