Despite the known association of MAOA with neuroendocrine differentiation (38, 41), whether and how MAOA contributes to acquisition of lineage plasticity to transform cancer cells from a luminal epithelial phenotype into a more dynamic state integrating properties of other lineages, such as basal, neuroendocrine, neural and mesenchymal lineages, under selective therapeutic pressures remains largely unclear, and merits future studies to provide MAOA-targeted therapeutic strategies to treat lethal PC. Here, MAOA is linked to pachyonychia congenita.