Squamous cell carcinoma-associated antigen was firstly used to diagnose squamous cell carcinoma tumor marker, which has high specificity for the diagnosis of various squamous cell carcinomas, and the diagnostic sensitivity for primary squamous cell carcinoma of the cervix can reach 50%-70%. In addition, it can also be used as a monitoring indicator for cervical cancer and lung cancer. The reasons leading to high squamous cell carcinoma-associated antigen are as follows: 1. The serum concentration increases with the aggravation of the disease, and if the treatment is effective that is, it decreases, and then rises again during the monitoring process, which often suggests that the tumor has recurred or metastasized; 2. It has been found that, apart from serving as a tumor marker for numerous cancers of squamous cell origins, squamous cell carcinoma-associated antigen in serum can also be found to be elevated in the detection of benign lung diseases In addition to being a tumor marker for numerous cancers of squamous cell origin, elevations are also found in tests for benign lung diseases, such as tuberculosis, adult respiratory distress syndrome, and tuberculosis;3 and in patients with a number of skin diseases, such as various forms of erythroderma and psoriasis vulgaris. And it is found that the wider the area of skin epidermal involvement, the more serious the epidermal keratinization and epidermal exfoliation of the disease squamous cell carcinoma antigen value is higher. Therefore, when the test results suggest that the squamous cell carcinoma antigen value is elevated, in addition to paying attention to related cancers, it is also necessary to consider the impact of skin exfoliation disease, so as not to cause unnecessary mental burden.