Real-time qPCR assays demonstrated a dramatic upregulation of MDK mRNA by IFN-γ in all examined cancer cell lines (Figure 2A), including the kidney cancer Caki-1, the lung cancer A549, the cervical carcinoma CaSki, the breast cancer BT549, and the colon cancer HCT116, which was further validated by Western blotting at the protein level (Figure 2B), suggesting that this is a shared regulation across different types of cancers. Here, MDK is linked to lung cancer.