The covariates included in the model are the estrogen receptor status (ER=1 for positive; =0 for negative), tumor size (Size = 1 for >2 cm; = 0 for ≤2 cm), lymph nodal status (Node = 1 for present; =0 for absent), age at diagnosis (Age = 1 for age ≤ 40; = 2 for 40 < age ≤ 50; = 3 for age > 50), MammaPrint (MammaPrint = 1 for high; = −1 for low), and the GGI defined by [3] (GGI = 1 for high; = −1 for low). This evidence concerns the gene ESR1 and neoplasm.