The arguments that mediate the pain mechanism of a neuroma include peripheral and central sensitization (9), expression of nerve growth factor (10), α-smooth muscle actin (α-SAM) (11), the change of neuroma fiber structure (2), connection between fibers, destruction of nerve function, and adrenaline sensitivity, etc. To avoid pain caused by neuroma, the injured or severed nerves should be treated with high quality. Here, NGF is linked to neuroma.