Using this KPC mouse model, we presently evaluated the effect of MAO inhibition via the β-carboline alkaloid harmine-hydrochloride (HH), a competitive and selective MAO-A inhibitor [50,51,52] on cancer-related muscle wasting, with regard to histomorphometry of fiber types, pro-inflammatory, -atrophic, and -apoptotic gene expression, capillarization, NMJ, intramyocellular glutathione (GSH) content and redox state, and relevant transcripts. This evidence concerns the gene MAOA and cancer.