Then, ALDH1-Hypoxyprobe double labeling of MDA-MB-231/MDA-MB-468 tumor tissues indicated that whereas tumors from control animals exhibited little hypoxia as determined by pimonidazole adduct (Hypoxyprobe) staining, tumors from Bevacizumab-treated mice displayed multiple areas of intense hypoxia. This evidence concerns the gene ALDH1A1 and neoplasm.