In this context, publications discuss the relevance of tumor-stroma as tumor microenvironment promoting cancer growth and initiation of metastasis [52], e.g. via estrogen-receptor-activation [53], via direct or indirect interactions of zinc with the immunosystem [54], via crosstalk between immune cells and cancer cells [55] or via zinc-mediated signaling in growth factor activation [53, 56]. This evidence concerns the gene ESR1 and cancer.