EN1 and breast cancer: For example, overexpression of EN1 is associated with pro-survival in basal-like breast cancer [29]; HOXB13 hypermethylation has been shown to be a late event in breast tumorigenesis and is associated with invasiveness [30, 31]; increased expression of DLX4 reduces invasion in vitro and metastasis in vivo [32]; and increased TBX15 methylation was a poor prognostic indicator in prostate cancer [33].