ESR1 and neoplasm: In fact, new molecules labeled other than [18F]FDG could be useful to predict response to NAC, analyzing aspects beyond glucose metabolism, in particular, the use of some radiopharmaceuticals in relation to tumor histotypes: [18F]-fluoro-17β-estradiol PET/CT in monitoring ER expression, [18F]-fluorothymidine for measurement cell proliferation, or [18F]-fluoromisonidazolethe for the evaluation of tumor-related hypoxia [47].