A synthetic lethal screen performed on Kras/p53/Lkb1 mutant GEMM derived NSCLC tumour lines and identified Deoxythymidylate kinase as a top hit thus coupling LKB1 inactivation to dependency on folate metabolism in order to supply nucleotides required for cellular replication (Liu et al, 2013). The gene discussed is KRAS; the disease is non-small cell lung carcinoma.