CRP and cancer: These can be attributed to the fact that serum CRP is a systemic inflammatory protein, which can be elevated in patients with other systemic inflammatory conditions, such as autoimmune disorders (rheumatoid arthritis, systemic lupus erythematosus, psoriasis, etc.), infections at a site other than joints (pneumonia, bronchitis, infected intravascular devices, urinary tract infections, etc.), and/or active cancer.