SMAD3 and skin basal cell carcinoma: Although previous studies have shown that SMAD3 can promote FLP in breast (including MDA-231) and gastric cancer cells (an effect that is indirectly related to SMAD3’s ability to transcriptionally upregulate actin-cross-linking protein fascin, an important molecular player of filopodial assembly),33,34 our MoT-outgrowth experiments in SMAD3 overexpression and knockdown settings demonstrated an inhibitory effect of SMAD3 on single cell 3D outgrowth of BCC.