ADORA2B and breast cancer: Interestingly, the cyclic peptide originally designed for growth inhibition in breast cancer [13, 14] showed the biggest suppression of ADORA2B, especially under hypoxic conditions, and reduced anchorage-independent colony formation to levels equal to, or lower than, those observed with the use of PSB-1115 and Bay 11-7082 (Figure 4E and 4F).