THY1 and breast cancer: Considering that the transmigration of breast cancer and melanoma cells is significantly decreased when cells have low levels of β3 integrin and that, in a preclinical mouse model, melanoma cells that normally metastasize to the lung cannot reach the target organ when β3 integrin has been silenced (Brenet, Martinez et al., 2020), the signaling mechanism triggered by the Thy-1–integrin interaction is important for cancer cell migration, invasion and transvasation both in in vitro and in vivo models.