We used combined data from previous papers (Sanchez-Cespedes et al, 2002; Carretero et al, 2004) and from Sanger institute's databases (Bamford et al, 2004) to analyse association of LKB1 mutations with mutations of KRAS, BRAF, and EGFR. Analysis of LKB1 mutation harbouring NSCLC cell lines (A-427, A549, NCI-H1395, NCI-H1666, NCI-H2122, NCI-H2126, NCI-H23, and NCI-H460) showed that five of the cell lines (63%) had concurrent LKB1 and KRAS mutations, two (25%) had concurrent LKB1 and BRAF mutations, and only one (13%) had neither KRAS nor BRAF mutations. The gene discussed is BRAF; the disease is non-small cell lung carcinoma.