PP1: The protein phosphatase 1 catalytic subunit and all its isoforms.
PP2A: The protein phosphatase 2A catalytic subunit and all its isoforms (designated PP2 in the human genome nomenclature).
PP2B: The protein phosphatsae 2B catalytic subunit and all its isoforms (also termed calcineurin A; designated PP3 in the human genome nomenclature).
PP1-like: All protein phosphatases that are more similar in sequence to PP1 than to PP2A and PP2B.
PP2A-like: All protein phosphatases that are more similar in sequence to PP2A than to PP1 and PP2B.
PP2B-like: All protein phosphatases that are more similar in sequence to PP2B than to PP1 and PP2A.