Ciro Santilli @cirosantilli 35

Determines what can or cannot happen when multiple queries are running in parallel.

See Section "SQL transaction isolation level" for the most common context under which this is discussed: SQL.

quoteinvestigator.com/2017/09/25/progress/ on Quote Investigator says it appeared in 1948. Can't easily check, but will believe it for now.

Integrates its RNA genome into the host genome.

Sounds complicated! The advantage is likely as in HIV: once inside the cell, it can remain hidden far away from the cell surface, but still infections.