MKI67 and granular cell tumor: The neural histogenetic origin of GCT was also proposed after immunohistochemical analysis of 15 oral lesion by Rejas et al. who found a positive staining for S-100, P75, NSE, and CD68 while other markers including Ki-67, Synaptophysin, HHF-35, SMA, EMA, Chromogranin, Progesterone, Androgen, and Estrogen were negative [29].