Smoking-related interstitial fibrosis (SRIF)
Smoking-related interstitial fibrosis (SRIF) is an abnormality in the lungs characterized by excessive collagen deposition within the walls of the air sacs (interstitial fibrosis). This abnormality can be seen with a microscope and diagnosed by pathologists.
Source: Wikipedia — Smoking-related interstitial fibrosis (SRIF) (CC BY-SA 4.0)