Blood–brain barrier, an Uncommon card

The card carries these facts from its Wikipedia article.

• The blood–brain barrier is formed by endothelial cells of the capillary wall, astrocyte end-feet ensheathing the capillary, and pericytes embedded in the capillary basement membrane.
• This system allows the passage of some small molecules by passive diffusion, as well as the selective and active transport of various nutrients, ions, organic anions, and molecules such as glucose and amino acids that are crucial to neural function.
• The blood–brain barrier restricts the passage of pathogens, the diffusion of solutes in the blood, and large or hydrophilic molecules into the cerebrospinal fluid, while allowing the diffusion of hydrophobic molecules and small non-polar molecules.

Rarity in WikiCards follows a year of Wikipedia page views: the most read articles become Epic and Legendary cards. The Blood–brain barrier article was read about 140,000 times in a year. ATK comes from the length of the article and DEF from its quality, so this card hits with 70 and blocks with 66: each hit it takes is cut by 26 %.

Open packs. Each pack holds five cards drawn from real Wikipedia articles, the rarest last, and the fifth card is always Rare or better. The odds are shown in the game. A free pack arrives every hour and two can wait, and the Coins you win in duels buy more packs.

The cards just above and just below Blood–brain barrier in the power ranking, all domains together.