GLP1R and neoplasm: It has been known since the late 1990s that GLP-1 lowers food intake; studies in rodents published in 1996 demonstrated that intracerebroventricular injection of GLP-1 had a marked effect in both fasting and fed states, and a publication in 1995 showed that a rodent tumor model that produced glucagon and GLP-1 was associated with severe anorexia (116, 178, 179).