Illegal weapons trafficking, human trafficking, and organ trafficking are three illicit trades in which smuggled goods are transported via clandestine ratlines, the supply meeting the demand, in a simple value transaction. Of the three, organ trafficking is perhaps the most rare and least understood. Those who get to close to the gangsters, and gangster governments, who perpetrate these crimes and come between the criminals and their profits tend to have a fairly short life span in many instances.
What is interesting about these value transitions is that they involve underground systems. I stress systems as the key here because these transactions do not happen in a vacuum. Organ trafficking in particular requires a unique form of underground railroad with skilled technicians who kidnaps victims, remove their organs, efficiently transport those organs, and then transplant them into waiting patients. With more overhead involved that trafficking women and children for prostitution, or smuggling drugs, it is interesting that more has not been exposed when it comes to the illegal harvesting of organs.
From recent reports out of Egypt, to rumors about ISIS, and industrial scale organ trafficking in China, the phenomena is very real and represents a gross human rights violation which is rarely spoken of in international forums.