MIR34A and lung cancer: Whereas, inactivation of the Mir34a and/or Mir34b/c genes in mice does not increase the rate of tumor formation, combination of Mir34 loss with other pro-tumorigenic lesions or treatments promotes tumor formation and progression in mouse models of prostate 13, pancreatic 14 and lung cancer 15 as well as in sporadic 16, colitis-associated 17 and inherited colon cancer mouse models 18.