They wanted "red alert".
https://en.wikipedia.org/wiki/Red_Alert
This is just an idiom for denoting a high alert state.
No, "Red Alert" is called when there is an attack imminent, incoming weapons detected, enemies sighted.
So a macrophage on "red alert" would be reacting to an active infection or disease.
alt Hacker News
No, "Red Alert" is called when there is an attack imminent, incoming weapons detected, enemies sighted.
So a macrophage on "red alert" would be reacting to an active infection or disease.