In both Kaposi’s sarcoma and xenograft breast cancer models, NAC treatment decreased tumorigenesis by inhibiting the angiogenic response in tumor cells [36], [37], while in a B16-BL6 melanoma model, NAC selectively inhibited type-IV collagenases including MMP2 and MMP9 [39], [43], key HIF-1 target genes involved in invasion and metastasis [1]. This evidence concerns the gene HIF1A and breast cancer.