For instance, in lung cancer patients, the methylation of SHOX2/PTGER4/RASSF1A in plasma DNA has been employed as a biological marker for identifying lung cancer and has found practical applications in clinical settings (Kneip et al., 2011; Weiss et al., 2017; Malpeli et al., 2019). Here, RASSF1 is linked to lung carcinoma.