38). For metastasis to occur, the disruption of cellular junctions is essential (Ref. 39). Several miRNAs regulate the expression of zonula occluden-1 (ZO-1), a major component of tight junctions (Ref. 40), e.g. miR-105 regulates the metastasis of breast cancer by inhibiting ZO-1 (Ref. 40). Furthermore, overexpression of miR-105 induces the metastasis of cancer cells to distant organs including the liver (Ref. 40). The cell-cell adhesion for the adaption of the premetastatic niche is promoted by oncogenic miR-105 through the tight junction protein ZO-1 (Ref. 40). The gene discussed is TJP1; the disease is breast cancer.