KRAS and lung cancer: Previous studies of laryngeal and lung cancers have reported that let-7a can regulate the expression of KRAS, and that menin is involved in let-7a miRNA processing (Johnson et al. 2005, Long et al. 2009, He et al. 2010, Oh et al. 2010, Guan et al. 2011, Wang et al. 2013, Gurung et al. 2014).