Despite the fact that our commercial risk score and subtype classification was derived based on NanoString RNA abundance profiling, our work confirmed the recent findings of the UK-OPTIMA prelim trial17 that most current breast cancer multiparametric risk tests provide broadly equivalent risk information for a population of women with ER+ breast cancers (Supplementary Fig. 6), but can exhibit discordance between tests at the individual patient level (Fig. 2, Supplementary Tables 3 and 4). Here, ESR1 is linked to breast cancer.