Interestingly, basal CDA and TYMP expression levels varied dramatically in different NSCLC cell lines including the KRAS mutant cell lines A549, H358, H441 and H2009, as well as KRAS wild type (WT) cell lines PC-9, H1993, H3122 and H2228 (Figure S5A, Additional file 1). Here, KRAS is linked to non-small cell lung carcinoma.