Found at higher levels in lSSc-PAH are cytokines characteristic of inflammatory response including: intercellular adhesion molecule 1 (ICAM-1), which was also increased in the microarray data and confirmed by qRT-PCR; vascular cell adhesion molecule 1 (VCAM-1); interleukin-8 (IL-8); interleukin-6 (IL-6); interleukin 1-beta (IL-1β); and tumor necrosis factor alpha (TNF-alpha). Here, CXCL8 is linked to pulmonary arterial hypertension.