Gelatin zymography, immunoblot and immunofluorescent analyses demonstrated the existence of murine cells with induced expression of MMP2, MMP9 or MMP14 in the teratoma (T) and in muscle (gastrocnemius) tissue adjacent to the teratoma (adjacent tissue, AT), but not in distant muscle (vastus) tissue with low teratoma proximity (neighbouring tissue, NT) (Fig. 3b, e–g and Supplementary Fig. 2d). Here, MMP9 is linked to teratoma.