AFP and liver cancer: In a study on the relationship between PFAS concentrations in human serum and liver cancer from 2019 to 2021, the highest serum concentrations of PFOS were found in different PFAS with a 100% detection rate, and the concentration of PFOS in human serum was found to be significantly associated with the incidence of liver cancer and the levels of alpha fetoprotein (AFP), indicating that exposure to PFOS can increase the risk of developing liver cancer [93].