The Verb болеть

Did you know that the verb болеть-заболеть and the short adjective болен (больна, больно, больны) are always used with the Instrumental case?

For example,

Я болею гриппом. I have a flu (I am ill with a flu)

Мы заболели коронавирусом. We caught the coronavirus (We got ill with coronavirus).

Она больна простудой. She has a cold (She is ill with a cold).