miR-221 and miR-222 regulate PIK3R1 and ETS1, respectively, in late EPCs. (A) A Venn diagram illustrates there were 845 probe sets commonly repressed by miR-221 and miR-222 (left). (right) A heat map showing the relative expression levels of these genes. Significant enriched biological processes among these genes according to the Gene Ontology database were also indicated. (B) Predicted duplex formed between ETS1 and miR-222/miR-221. (C) RT-qPCR results show ETS1 (left) and ETS2 (right) expression levels in late EPCs from health controls (PB) and CAD patients. **: p < 0.01 by Mann–Whitney test. (D) Reporter activity of the ETS1 on two 3′UTR reporter constructs containing the conserved binding site (upper) and poorly conserved binding site (lower) after cotransfection with the miR-221, miR-222 or empty vector into 293 T cells (n = 3). (E) miR-221 targets PIK3R1 in late EPCs. RT-qPCR show the levels of PIK3R1 in health and CAD late EPCs (upper), or in late EPCs overexpressed with miR-221. miR-222, or both (lower) (n = 3). (F) A model of miR-221 and miR-222 regulate EPC motility and tube formation functions through PIK3R1 and ETS1, respectively.