The dichotomization of patients into PIK3CA-mutant subgroups with high and low cfDNA levels showed that the mutant cfDNA-high level subgroup exhibited significantly shorter recurrence-free and overall survival rates than the cfDNA-low level subgroup and nonmutant patient group, indicating that PIK3CA mutation status is a significant and independent prognostic factor for patients with BC [33]. The gene discussed is PIK3CA; the disease is breast cancer.