To confirm differential gene expression levels in the three breast cancer subtypes, Her2+, ER + and TNBC, we selected 6 genes (ITGA3, ITGA5, OXTR, WNT5B, BCAR1, FZD1) with significantly different levels of expression based on our microarray studies and validated their expression levels by qRT-PCR. This evidence concerns the gene ITGA3 and breast cancer.