SAMHD1 and breast cancer: Interestingly, SAMHD1 positivity was associated with grade III tumors (p = 0.025), higher levels of Ki67 after NACT (p = 0.017) and increased risk of recurrence (p = 0.005), suggesting that SAMHD1 expression might represent a relevant prognostic biomarker for breast cancer post-NACT (Table 1, Fig. 1D).