KLK8 and neoplasm: To classify a new tumor sample, one evaluates the sample’s expression levels for three predictor genes (biomarkers): first, a keratin predictor gene is evaluated (KLK8, or one of its keratinization surrogates such as KRT6C, IVL, SPRR1B, KRT14, KRT16), where high values would label the sample as “Keratin” and low values would lead to the next predictor.