The author was referring to the steam holiday gems. They are a new feature (released yesterday) in which a steam user can turn their extra junk cards/backgrounds/emotes into gems.. These gems can be used to buy more cards; or, during the upcoming holiday event only, to bid on games.
Acinar cells. 1  Acinar cells are the exocrine (exo=outward) cells of the pancreas that produce and transport enzymes that are passed into the duodenum where they assist in the digestion of food.
Microglial cells are the dominant antigen presenting cells in the central nervous system. Under resting conditions the expression of the molecular complex for presenting antigen, the major histocompatibility complex II (MHCII) and co-stimulatory molecules such as CD80, CD86 and CD40 is below detection.