KRT20 and granular cell tumor: Therefore, additional immunohistochemical staining was performed which showed positivity for cytokeratin 7, cytokeratin 20 and Caudal Type Homeobox 2 (CDX2) in both the current peritoneal metastasis as well as the previous teratomatous type II GCT metastasis (Fig. 2a and supplementary figure 1).