ST6GALNAC5 and breast cancer: Other notable downstream targets of SOX11 included MEX3A, which encodes an RNA-binding protein, that marks slowly proliferating multipotent stem cells in mouse intestine (Barriga et al., 2017) and totipotent cells in C. elegans (Pereira et al., 2013); MMP11, ST6GALNAC5, and TUBB3, which are highly expressed in breast cancers that metastasize to brain (Bos et al., 2009; Kim et al., 2015; Lee et al., 2016).