Sample collection, processing and RNA extraction: Whole blood was collected in triplicate followed by peripheral blood mononuclear cells (PBMCs) separation in a subset of samples.

The following sample collection tubes were used for the study: RNAgard^®, PAXgene^® RNA, EDTA, ACD-A, and CPT tubes. The PBMC separation was done using standard procedures for CPT tubes, and magnetic bead, LeukoLOCK^™ and LSM methods. The samples were then stored at either 4°C (Cold) or -80°C (Frozen) and shipped overnight (o/n) for follow-up RNA extraction. Next, they were treated with one or more of several different RNA extraction procedures: Biomaxi Precip Buffer/ PAXgene^® Blood miRNA, PAXgene^® Blood miRNA, TRIzol^® LS, ACK Lysing Buffer/ Qiagen miRNeasy, and TRIzol^® Reagent manufacturer’s protocol.