Previous studies have also shown that classification of NSCLC into histological subtypes can be achieved using relatively simple methods, using both microarray and RNA-seq data, for example a nearest class centroid approach using differentially expressed genes and Pearson correlation as a similarity measure57, or a two gene (KRT5 and AGR2) expression ratio which classified LUAD and LUSC samples with relatively high accuracy58. Here, KRT5 is linked to non-small cell lung carcinoma.