Although some studies have reported that inhibiting the activity of GSK3β can suppress the growth of various types of cancers such as brain cancer (Furuta et al., 2017), breast cancer (Ugolkov et al., 2016), colorectal cancer (Salim et al., 2013), ovarian cancer (Cao et al., 2006), and leukaemia (Wang et al., 2008), indicating that GSK3β exerts a tumour promoter role, GSK3β has been regarded as a tumour suppressor factor in other studies. This evidence concerns the gene GSK3B and breast cancer.