Second, the TCGA BRCA dataset (n = 821) with PAM50 subtypes called by RNAseq was used to validate the differentially expression of COL2A1, COL11A1, COL6A1, COL6A2, THBS1 and LUM among four breast cancer molecular subytpes in an independent cohort (Fig. 6). This evidence concerns the gene COL6A2 and breast cancer.