PAX8 and cancer: Normally undetectable in adult tissues, Pax genes are overexpressed in various cancers, in link with their embryonic role.30,31 For instance, Pax3, which is important for NC- differentiation into melanocyte during development,32 is overexpressed in melanoma.30,33,34 Pax2 and Pax8, which play an important role in early urogenital development, are essential for tumor progression and survival in several cancers of urogenital origins.31