HDLs are considered part of the innate immune system and can traffic immunomodulatory molecules or potentially harmful substances.

“those proteins have a multitude of functions dan rader years ago always tell me tom hdls are part of the innate immune system they're little fire engines they're carrying god knows what that could go into wherever there's inflammation in your body a swollen knee any in-tissue injury or your arterial wall and they could maybe help what's going on there because they're trafficking immunomodulatory functionality molecules or they could go in because oh my god these are corrupt hdls they're carrying bad junk which is further inflaming it we have no way of measuring those now i mean researchers can do lipodome analysis of the phospholipids the sphingolipids the ceramides that are in hdls we can you know they've identified over 150 different proteins that might be on an hdl now they're not all on one given hdl but some hdls may have two of this protein none of that and you have different groups of hdls in my analysis they're different types of fire engines carrying different things”