There is also a lack of PSAT1-targeted drugs and related clinical trials, with only one registered clinical trial (NCT02103920) for retrospective expression detection of glycine/serine metabolism pathway molecules (e.g., PSPH, PSAT1, SHMT1, and GLDC) in solid tumors such as colorectal, lung, and breast cancers. The gene discussed is SHMT1; the disease is breast cancer.