In a mouse model injected with B16F10 skin melanoma cells that progressed to lung metastatic melanoma, astaxanthin induces apoptosis in melanoma cells within the lung by inhibiting key proteins such as Bcl-2, cyclins D1 and E, NF-κB, ERK, mitogen-activated protein kinase kinase (MEK) and matrix metalloproteinases 1 and 9 (MMP-1 and -9), while increasing cleaved caspase-3 and -9, ataxia telangiectasia-mutated kinase (ATM) and p21 [137]. This evidence concerns the gene MMP1 and metastatic melanoma.