Therefore, we next analysed Pfn1 expression at the protein level by quantitative IHC in a BC TMA consisting of a large panel (>500 samples) of primary tumours isolated from invasive BC patients and compared the relative Pfn1 expression between low nuclear grade (1) vs high nuclear grade (2 and 3) tumours (Fig. 1c). This evidence concerns the gene PFN1 and breast cancer.