KRT20 and Merkel cell skin cancer: in 1972 (11), MCC took its name from some structural and immunohistochemical (IHC) features that share with Merkel cells (MCs), in particular the expression of ion channel Piezo 2 (12), cytokeratin 20 (CK20), chromogranin A, synaptophysin, and neuropeptides (13–17).