The authors hypothesized a tumerogenic role of aberrantly expressed EV circ-CYP24A1 in cSCC, as supported by an observed uptake of circ-CYP24A1 by A431 and SCL-1 cells co-cultured with PKH67-labeled EVs.34 Furthermore, EVs transfected with si-circ-CYP24A1, which knockdowned circ-CYP24A1, restrained proliferation, migration, and invasion of cSCC cells and induced their apoptosis. This evidence concerns the gene CYP24A1 and skin squamous cell carcinoma.