Furthermore, myeloid cells had increased levels of genes involved in chemotaxis (CXCL1, CXCL8, CXCL10, CCR1, CXCR1 and CXCR2) and genes involved in inflammation (IL1B and TNFSF10) in SJP polyps compared with JPS or PJS polyps. Here, CXCR1 is linked to Peutz-Jeghers syndrome.