Fig. 1
From: p16INK4A expression is frequently increased in periorbital and ocular squamous lesions
a Histology of the negative control, taken from a pterygia (20x, magnification). c Immunohistochemical staining for p16 in the same case (20x magnification). Note the lack of staining in epithelial cells. b, d Positive control p16 immunohistochemical staining, taken from a squamous cell carcinoma in-situ from cervix (4x and 20x, respectively). Note both cytoplasmic and nuclear reactivity