The body uses machine learning?

I was reading through machine learning methods when I had a thought, "Wasn't some of these how the body programmed its cells?"

 Like with the Thymus
The Body continouly produce T-Cells then runs them through examples of the various cells in the body and examples of remembered bad cells.
If the T-cells attack a good cell or don't attack a bad cell, they are recycled
That sounds to me like the same method used for basic machine learning.

Is machine learning called something different when done by the body?