Glioblastoma is one of the most aggressive brain tumors known to medicine — and the biology behind why makes it especially devastating. 🧠 Neurons and mature muscle fibers don't typically divide, which is why they rarely form tumors. But glial cells do divide — and when they accumulate enough DNA mutations, that division can spiral out of control. The result is a glioblastoma, most commonly arising from astrocytes. Unlike meningiomas that grow on the outside of the brain and compress inward, gli