(A) RT-qPCR quantification of relative levels of pri-miR-21, pre-miR-21, miR-21-5p and miR-21-3p levels in healthy human skin and human squamous cell carcinomas (SCC). pri-miR-21 Healthy skin vs SCC P = 0.043; pre-miR-21 Healthy skin vs SCC P = 3E-05; miR-21-5p Healthy skin vs SCC P = 7E-05; miR-21-3p Healthy skin vs SCC P = 1.4E-06. ≥ 5 independent biopsies per condition. 