One of the key reasons for cancer mortality is the highly invasive behaviour of cancer cells, which is often due to aggressive metastasis. Metastasis is facilitated by various growth factors and cytokines secreted from cells of the immune system, which operate through various signaling pathways. Remarkably, these signaling pathways enter the nucleus through the nuclear pore complex (NPC), which is supposed to act as a doorkeeper to the nucleus. NPC is, in fact, a nanomachine consisting of multiple copies of about 30 different proteins, collectively called nucleoporin.