CXCL6 and Dowling-Degos disease 1: Time-dependent upregulation of CCL11, CCL3, CXCL1, and CXCL10 has been suggested, as well as an inverse relationship between serum levels of CCL11 and VAS in patients with chronic radicular back pain.31 Regarding DDD, CCL5 and CXCL6 have been found to be upregulated in serum,25 and serum IL18 has been correlated with DDD severity.73 We were not able to replicate these findings.