N-Glycolylneuraminic acid (Neu5Gc) is a sialic acid molecule found in most non-human mammals including apes and monkeys. Humans lack Neu5Gc, but has only the alternative N-acetylneuraminic acid (neu5Ac). It is estimated that a mutation about 2.5 million years ago in the line of walking apes that became the first primitive humans had this mutation. It is thought to offer protection against chimp type malaria, but not against the more recently evolved human forms of malaria that are just fine with Neu5Ac. Neu5Gc is found associated with tumors.
Neu5Gc in red meat and organs may pose a significant health hazard

Neu5Gc, a non-human sialic acid sugar molecule common in red meat that increases the risk of tumor formation in humans, is also prevalent in pig organs, with concentrations increasing as the organs are cooked, a study by researchers from the UC Davis School of Medicine and Xiamen University School of Medicine has found.
The research, published in Glycoconjugate Journal Sept. 9, suggests that Neu5Gc may pose a significant health hazard among those who regularly consume organ meats from pigs.
Neu5Gc is naturally found on cell surfaces in most mammals but not in humans. It gets incorporated into human cells by eating meats, organs and some dairy products.
Previous studies have shown when Neu5Gc is incorporated into human tissues, the immune system recognizes it as a foreign threat, producing antibodies to counter it. Repeated consumption of these meats then causes chronic inflammation, which has been known to increase risks of tumor formation. Neu5Gc has been linked to cancer as well as cardiovascular and other inflammatory diseases, including some bacterial infections. https://www.ucdmc.ucdavis.edu/publis...newsroom/11551
What is important is that our antibodies in some cases attack cells containing Neu5Gc which we get from red meat and milk products. Fish and chicken are low in Neu5Gc. Probably not the time to go and make wild diet changes, since the scientific community is still studying this. But it is worth paying attention to new discoveries in this field. If interested I suggest googling these molecules which are present in the materials coating the cells of our bodies. Some people speculate it may have something to do with our greater intelligence over our ape relatives.