microRNA-21 in the PDAC stroma is expressed in activated myofibroblasts.

<p>(<b>A</b>) miR-21 <i>in situ</i> hybridization and co-immunofluorescence for α-SMA and nestin on serial sections of two human PDAC tumors (Whipple resection - WR 22 & 28) reveals miR-21 expression in a subset of activated myofibroblasts, not exclusive to stellate cells (nestin positive). miR-21 positive staining is white in the merge. (<b>B</b>) High-power magnification (40x) again reveals miR-21 expression in a subset of α-SMA expressing myofibroblasts. Vimentin, a marker for quiescent fibroblasts, does not localize with miR-21.</p>