Similarly, neutrophil clearance of Pseudomonas aeruginosa is impaired by the enhanced PTP1B expression observed with infection through negatively regulating the Toll-like receptor 4 (signal transducer and activator of transcription factor 1)-inducible nitric oxide synthase (TLR4-STAT1-iNOS) signalling pathway and nitric oxide (NO)-mediated bacterial killing [36]. Here, PTPN1 is linked to infection.