FPR1 and Crohn disease: aureus-derived formyl peptide receptor-like 1 (FPRL1) inhibitory protein impairs FPR-mediated Ca2+ signaling and neutrophil chemotaxis.316 Notably, various drugs can interfere with FPR function; for instance, cyclosporins exhibit inhibitory activity against FPR1.317 Apart from its upregulated expression in inflammatory diseases, FPR1 is also highly expressed in neutrophils in other diseases, including colorectal cancer, emphysema, and Crohn’s disease.318–320 The swift upregulation of FPR1 expression following stimulation suggests the receptor’s preformed presence within the cell.