MALAT1 and cancer: Overexpression of MALAT1 mRNA was detected in 14% (63/446) of breast tumours, confirming the oncogenic role of MALAT1. Indeed, MALAT1 is overexpressed in several cancer types, including lung, colon and hepatocarcinoma, and overexpression of MALAT1 in various cell lines enhanced cell proliferation, whereas in nude mice, increased levels of MALAT1 promoted tumour formation (Ji et al, 2003; Guo et al, 2010; Gupta et al, 2010; Gibb et al, 2011; Schmidt et al, 2011; Lai et al, 2012).