Furthermore, M protein shuttles between the nucleus and cytoplasm: during early infection, it enters the nucleus via importin β1‐dependent nuclear import, while later in infection, it returns to the cytoplasm through CRM1 (i.e., Chromosome Region Maintenance 1; also known as exportin 1 or XPO1)‐mediated nuclear export to participate in viral assembly [299, 300, 301]. The gene discussed is XPO1; the disease is infection.