PF4 and systemic sclerosis: Second, our initial measurement of CXCL4 occurred prior to the initiation of immunosuppressive therapy for SSc-ILD; thus, the reported baseline levels of CXCL4 are likely closely related to the underlying disease state without any interference from disease-modifying therapies (patients were ineligible for SLS II if they had received CYC or MMF for >8 weeks ever in the past, or they had received intravenous CYC more than twice ever in the past, or were taking CYC/MMF/any medication with potential disease-modifying activity within 30 days of randomization).