Wang et al. observed an increased expression of MMP2 and MMP9 (matrix metallopeptidase 9) in choroidal malignant melanoma (CMM) compared to non-tumoral choroidal tissues; the authors demonstrated that both metalloproteases are targeted by miR-296-3p, which showed reduced expression in CMM cell lines compared to normal melanocytes. Here, MMP9 is linked to familial congenital mirror movements.