A promoter competition model (as described by Cho et al.)(74), proposed to unravel the puzzle of c-myc and PVT1 interactions indicated that the PVT1 promoter regulates MYC's transcription in breast cancer as a result of the PVT1 promoter (not PVT1 RNA) acting as a DNA boundary element to regulate the transcription of MYC. This evidence concerns the gene MYC and breast cancer.