Studies that have deployed knockdown or knockout of ERK5 (or MEK5) by siRNA have shown therapeutic potential for ERK5 in prostate cancer (Clapé et al., 2009), bladder cancer (Noguchi et al., 2011), breast cancer (Ortiz-Ruiz et al., 2014), KRAS-dependent pancreatic ductal adenocarcinoma (PDAC) (Vaseva et al., 2018), and in melanoma (Hayashi et al., 2005; Giurisato et al., 2018; Tusa et al., 2018; Giurisato et al., 2020). The gene discussed is MAPK7; the disease is breast cancer.