Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Tracheobronchomalacia ?
    ### Response:
    Tracheobronchomalacia (TBM) is a rare condition that occurs when the walls of the airway (specifically the trachea and bronchi) are weak. This can cause the airway to become narrow or collapse. There are two forms of TBM: a congenital form (called primary TBM) that typically develops during infancy or early childhood and an acquired form (called secondary TBM) that is usually seen in adults.
    