CCL19 and systemic sclerosis: A total of 10 SSc fibroblast subpopulations were identified by characteristic gene expression, including SFRP2hi fibroblasts (SFRP2/WIF fibroblasts, SFRP2/PRSS23 fibroblasts, PCOLCE2 fibroblast), APOE-defined cells (MYOC/FMO1/APOElow fibroblasts, CCL19/C7/APOEhi fibroblasts), CRABP1 fibroblasts, COL11A1 fibroblasts, POSTN/ASPN fibroblasts, ANGPTL7 fibroblasts, and proliferating fibroblasts.