MC1R and breast carcinoma: Fig 2 shows the studies without and with the substrate of 1.0 μM α-MSH and 111In-labeled 3-arm and 4-arm DOTA-α-MSH in B16-F1 melanoma cells with high MC1-R expression and 4T1 breast cancer cells with low MC1-R expression measured with real-time qPCR.