GAPDH and invasive breast carcinoma: Further, The Cancer Genome Atlas (TCGA) data set of 844 patients with invasive breast carcinoma (RNA sequencing version 2 analysis [RNA Seq V2] normalized gene expression with RSEM output [RSEM]) revealed a correlation between PDPN mRNA level and LN metastasis, showing higher levels of PDPN mRNA (PDPN mRNA expression normalized to Gapdh) associated with more LN metastasis (Fig 5A).