KRT5 and systemic sclerosis: In health, basal keratinocytes express high levels of the cytokeratins 5 and 14 (K5 and K14), whereas these factors are lost as the keratinocytes commit to differentiation and migrate upwards, switching to cytokeratins 1 and 10 (K1 and K10) [32], a process which is markedly altered in SSc, where basal K14 positive cells abnormally persist into the spinous and granular layers, whereas induction of K10 is delayed [11,15].