[pfdietz]

-ab means it's an antibody. There are many kinds of antibodies, not just to those two proteins.

[semi-extrinsic]

And -mab means monoclonal antibody. But your point still stands, there is a huge number of -mab drugs out there today.

[pfdietz]

It's a really great technology, and not just for drugs. It deservedly won the Nobel Prize in Medicine in 1984.