Serious, sometimes fatal infections, lymphoma, and other cancers have happened. don't start xeljanz xr if you have an infection. tears in the stomach or intestines, low blood cell counts, and higher liver tests and cholesterol levels have happened. your doctor should perform blood tests before you start and while taking xeljanz xr, and monitor certain liver tests. tell your doctor if you were in a region where fungal infections are common, and if you have had tb, hepatitis b or c, or are prone to infections. xeljanz xr can reduce the symptoms of psoriatic arthritis. don't let another morning g...