HIF-1α induces EMT through activation of EMT-associated transcription factors TWIST, SNAIL, SLUG, SIP1, ZEB1, and MMPs, the key players in invasion and metastasis, as shown in several in vitro cancer models, including head and neck squamous carcinoma, hepatocellular carcinoma, colorectal cancer, ovarian cancer, and renal cell carcinoma cell lines [114,115,116] (Figure 3). Here, SNAI1 is linked to ovarian cancer.