HPN and breast cancer: Low TMPRSS1 mRNA expression was associated with both poor breast cancer-specific survival (log rank, P = 0.030; Cox regression analysis, P = 0.034; HR, 2.344; 95 % CI, 1.065-5.160; Fig. 4a) and poor overall survival (log rank, P = 0.006; Cox regression analysis, P = 0.007; HR, 2.392; 95 % CI, 1.276-4.484; Fig. 4b) in patients who were treated with radiotherapy.