MDM2 and lung cancer: Gui et al (24) found that the MDM2 309G allele is a low-penetrant risk factor for developing lung cancer in Asians, yet Bai et al (23) conducted a meta-analysis involved in the same research and found that the MDM2 SNP309 GG genotype enhanced the risk of lung cancer development in never smokers with statistical significance, but no statistically significant was noted in Asian and European individuals.