ERBB2 and breast cancer: On the basis of the findings from the ACRIN 6657 trial in 230 patients with hormone receptor HR-positive/HER2-negative, HER2-positive, and HR-negative/HER2-negative (TNBC) breast cancer, Hylton et al. and Jafri et al. first reported FTV as an important biomarker in NAST treatment response assessment [20,21,30].