Epidermal differentiation in healthy control and patient H.

<p>(<b>A</b>) Light microscopy images of skin biopsies from control and patient H immunolabeled with antibodies specific for keratin 14 (K14) and Ki-67 with hematoxylin as nuclear counterstaining reveal an abnormal differentiation process in patient skin. (<b>B</b>) Confocal microscopy images of the same control and patient skin biopsies immunostained with antibodies specific for filaggrin, involucrin, and loricrin with DAPI (blue) as nuclear counterstaining. The patient skin biopsy shows a thickening of the stratum granulosum compared to the healthy control. Arrows indicate hyperplastic basal cells in the patient skin. The thin dashed lines indicate the interface between the stratum granulosum and the stratum corneum as well as the upper edge of the stratum corneum. Scale bars, 50 µm.