Similarly, the pharmacologic inhibition of VIP signaling using VPAC1 and VPAC2 peptide antagonists in vitro demonstrated variable anti-tumor responses depending on cancer histology and the cell line tested, with positive responses primarily seen in pancreatic, colorectal, gastric, and breast cancer models [5,17,18,19,20,21]. The gene discussed is VIPR2; the disease is breast carcinoma.