Symptom burden, as measured by the Cystic Fibrosis Respiratory Symptom Diary (CFRSD)-Chronic Respiratory Infection Scale (CRISS) in PwCF has been associated with c-reactive protein (CRP), a marker of systemic inflammation [16], suggesting that symptom burden increases in response to inflammation or infection, and may be a useful measure for predicting treatment outcomes. This evidence concerns the gene CRP and infection.