A cloud map of author keywords is shown in Figure 8, apart from the keywords of ferroptosis (n=27), iron (n=8), reactive oxygen species (n=5), cell death (n=4), erastin (n=4), GPX4 (n=3), autophagy (n=3), hepatocellular carcinoma (n=3), head and neck cancer (n=3), necroptosis (n=3), and sorafenib (n=3) were these keywords with more than 3 times of frequency. Here, GPX4 is linked to head and neck cancer.