Inhibition of ADORA1 reduced the binding activity of ER to its target gene indicating its role for the transcriptional activity of ER on oestrogen stimulation.51 By decreasing COL4A2 mRNA levels through miR-29b may be contribute to the tumorigenicity in ER-positive BC cells.52 The aforementioned studies have revealed the potential role of these biomarkers in ER-related pathways and may affect RXRG expression. This evidence concerns the gene COL4A2 and breast cancer.