CCL21 as a potential biomarker for pulmonary arterial hypertension in systemic sclerosis.

We thank Zhou and co-workers for their interest regarding our newly published manuscript on the role of CCL21 in pulmonary arterial hypertension (PAH) associated with systemic sclerosis (SSc). Here, we want to respond to their concerns. Genome-wide association studies (GWASs) have been foreshadowed to be a major advance in biomedical discovery, with many robust associations to complex diseases. However, although there are found polymorphisms with SSc, there are, to date, no existing genetic loci for SSc-PAH. Secondly, despite this success, GWAS studies have met considerable skepticism regarding their clinical applicability; mainly arising from their unclear functional consequences. This article is protected by copyright. All rights reserved.