MDK and neoplasm: To extend our knowledge about the secretome between HIF-1α expression under normoxic conditions and HIF-1α knock down under hypoxic conditions in H1299 cells used in this study, we profiled the top 14 cytokines secreted from HIF-1α-induced H1299 cells and selected MDK, which showed the greatest differences between two samples, for further investigation by examining their effects on the tumor microenvironment (Figure 1D).