PNLIP and obesity due to melanocortin 4 receptor deficiency: Obesity is a huge burden on social costs and is linked to many chronic diseases and cancer, Pancreatic triacylglycerol lipase (PNLIP) are the primary lipases secreted by the pancreas, and is responsible for breaking down dietary lipids into unesterified fatty acids (FAs) and monoglycerides (MGs).