In the absence of Pin1, the levels of activated Notch1-IC are variably affected, appearing increased in SilAll and Jurkat cells, whereas decreased in Molt3 and P12-Ichikawa cells (Figure 1b), highlighting the lack of correlation between high Pin1 levels and the upregulation of Notch1-IC protein levels in human T-ALL cells, as instead previously described in breast cancer.19, 20 Notably, the levels of N3IC decreased in all the cell lines analyzed, independently of Notch1 activation status, as revealed by the immunoreactivity to the anti-Notch1Val1744 antibody (Figure 1c). This evidence concerns the gene PIN1 and breast cancer.