KLK4 and cystic fibrosis: Cystic Fibrosis sweat proteome was characterized by an increased level in (i) proteases (Kallikrein 7 and 13, Phospholipase B domain containing 1, Cathepsin A L2 and B, Lysosomal Pro‐X carboxypeptidase, neuraminidase); (ii) proinflammatory proteins (Annexin A2, Chitinase‐3‐like protein 1); (iii) cytochrome c; (iv) Transglutaminases 3 and 5; and (v) Toll‐interacting protein (TOLLIP).