PSTPIP1 and arthritic joint disease: Interestingly, mutations in the F-BAR domain (E250Q and A230T) of CD2BP1/PSTPIP1 are associated with the PAPA syndrome (acronym for Pyogenic Arthritis, Pyoderma gangrenosum, and Acne), a rare inherited auto-inflammatory disease, and to disrupt the binding of PTP PEST [125].