In addition, after you quit smoking, the cilia in your throat and upper airways can grow back and start to function again. Cilia are tiny cells that assist with clearing mucous from the airways and help you to breathe properly.Lung regeneration after smoking usually occurs from one month after quitting until about nine months after quitting. In recent years, there has been a lot of research into growing lungs artificially.ilia are tiny cells that assist with clearing mucous from the airways and help you to breathe properly. Lung regeneration after smoking usually occurs from one month after quitting until about nine months after quitting.