Analysis of PBMC from patients with SSc revealed Siglec-1 and other IFN-regulated genes were overexpressed in patients with dcSSc, whereas patients with lcSSc with PAH overexpressed IL-13RA1, ICAM-1, CCR1, JAK2, and MCR1 (123, 125, 126). This evidence concerns the gene IL13RA1 and pulmonary arterial hypertension.