In a recent study [11], we could show that inclusion of cell‐penetrating peptides, comprising the ETD region of HIF‐1α in various mutant forms, in the culture medium of three different types of cancer cells could drastically reduce HIF‐1 activity (without affecting HIF‐2) and inhibit proliferation as well as migratory and colony formation abilities of the cells and trigger apoptotic death only under hypoxic conditions. Here, HIF1A is linked to cancer.