The identification of p57Kip2 as an important player in these placental diseases has led to the development of diagnostic procedures based on immunohistochemistry using anti-p57Kip2 antibodies and histological analysis for the characterization of hydatidiform moles and PMD, and their differential diagnosis [179,180,181]. This evidence concerns the gene CDKN1C and Pelizeaus-Merzbacher spectrum disorder.