SERPINA1 and breast cancer: Accordingly, in consideration of the inherent deficiency of TNM stage system, a novel prognostic model on the basis of the four ARGs (ATG4A, IFNG, NRG1 and SERPINA1) and two clinicopathological factors (age and TNM stage) was constructed to improve individual prediction of 5‐year OS and achieve effective subgroup stratification for BC patients.