MT-CO2 and neoplasm: Finally, proteins involved in tumor migration, invasion, malignancy and cell adhesion (Ctsd or Cathepsin D [13], MTCO2, Tpd52l2 [14], Rab5c [15], Smarcc1 [16]) were also found to be exclusively expressed or significantly up-regulated by the AI tumorspheres compared to the AD cells (Table 1).