The selectivity of TGP-377 was assessed via miRNA profiling. First, we studied the effect of TGP-377 on miRNAs predicted to modulate VEGFA production by Targetscan. These miRNAs include miR-15b, -16, -20a, -20b, -195, -377, and -205. Analysis of their precursor hairpins showed that only pre-miR-377 contains the 5'AAC/3'U_A target site. Analysis of the entire miR-ome produced in HUVEC cells showed that amongst >200 miRNAs, only miR-377 was significantly inhibited by >50 % (p <0.001) upon treatment with TGP-377 (Fig. ). Importantly and in contrast to C1, pre-miR-421 is not affected (orange triangle in volcano plot; Fig. ), demonstrating that TGP-377 is selective for pre-miR-377 and that modular assembly can overcome liabilities of selectivity while at the same time enhancing potency of monomeric compounds. As miR-377 decreases the levels of Vefga mRNA, application of TGP-377 also enhanced the levels of Vegfa mRNA by >50% at 500 nM (Fig. ).