BCL2 and skin basal cell carcinoma: In addition to histopathology, various scientific works [24] have attempted to identify immunohistochemical markers that could reliably differentiate between TB and BCC, including CD34 positivity of the stroma fibrocytes in TB versus negative stroma fibrocytes in basal cell carcinoma [25,26,27]; different BCL-2 expression, that is diffusely positive in epithelial cells of BCC but only marks the peripheral layer of cells in TB [28,29]; finally, the number of CK20-positive Merkel cells, more abundant in TB than in BCC.