These subtypes have significantly different clinical behaviors: the KP subtype has low latency (12) and a higher metastatic proclivity; the KL subtype is more aggressive than the KP subtype and selectively sensitive to the treatment of deoxycytidine analogs, for example, gemcitabine; KC subtype is characterized by lacking NKX2-1 expression and poor prognosis. Here, NKX2-1 is linked to keratosis pilaris.