Finally, an interrogation of the GSE59515 dataset from a study with comparative gene expression profiling of ER+ breast tumors receiving neoadjuvant letrozole treatment for 2 weeks (Selli et al. 2016) showed that the expression of ECM1 is increased in post-treatment tumors compared to pre-treatment tumors (Figure 2(F)). This evidence concerns the gene ESR1 and breast neoplasm.