Overexpression of HER3 is associated with the development of multiple cancers, including breast, lung, prostate, gastric, bladder, melanoma, colorectal and squamous cell carcinomas (Beji et al., 2012 ▸; Hayashi et al., 2008 ▸; Lipton et al., 2013 ▸; Luckow et al., 1993 ▸; Nielsen et al., 2015 ▸; Qian et al., 2015 ▸; Reschke et al., 2008 ▸; Tanner et al., 2006 ▸; Siegfried et al., 2015 ▸). This evidence concerns the gene ERBB3 and cancer.