Proliferative foci is the process of tissue repair, when the affected tissues form proliferative foci after localized damage, mostly seen in the repair of lung infection or tuberculosis. 1. Repair after lung infection: when the patient’s lung tissue is stimulated by inflammation and localized damage, after a certain period of time, the damaged part of lung tissue will undergo cellular self-repair and proliferation will occur, forming a proliferative foci, which is like a scar after a person touches it and doesn’t need too much attention. Therefore, when the patient’s chest X-ray and lung CT show proliferative foci with uneven and relatively high density in the lungs, the patient can be monitored by regular lung CT examinations and no special treatment is needed. Lung CT can be repeated regularly for monitoring. 2. Tuberculosis: when the patient has chronic tuberculosis, after a period of standardized and systematic treatment, there will be proliferation in the lungs when checking lung CT, which indicates that the tissue is in a relatively stable state, and regular monitoring can be done.