For the studies regarding the prognosis of intrinsic subtypes and the efficacy of trastuzumab for HER2+ subgroup in pT1a-bN0M0 breast cancer patients, either graphic inspection of funnel plots or quantitative evaluation from Begg's test indicated the absence of publication bias in DFS, OS, LRFS and DDFS (data not shown). This evidence concerns the gene ERBB2 and breast cancer.