In the present work we sought at analysing consecutive jaw cysts with residual epithelium to look for the potential value of CK17 and bcl2 IHC (the two most consistent and distinguishing IHC reactions available, Fig. 1) in the proper diagnosis of these cysts and see how these stains (along with clinical and radiological data) are helpful in the differential diagnosis, especially the diagnosis of OKCs. The gene discussed is KRT17; the disease is jaw cancer.