Firstly, we observed increased surface expression of CXCR4 on peripheral psoriatic neutrophils compared with healthy controls as measured by mean fluorescence intensity (MFI) of CXCR4 (Fig. 1a, Supplementary Fig. 1a), which was positively correlated with Psoriasis Area Severity Index (PASI) (R = 0.37, p = 0.0012, n = 25) (Fig. 1b). The gene discussed is CXCR4; the disease is psoriasis.