Plastic bronchitis is classified into two types according to the constituents of the formed casts: Type 1 PB is characterized by the formation of highly cellular inflammatory casts, mainly eosinophilic cells, and is usually associated with diseases such as asthma, cystic fibrosis, non-cystic fibrosis bronchiectasis, sickle cell disease, and smoke inhalation, while type 2 PB is composed of acellular materials composed of fibrin and mucin, which is usually linked to post-surgical correction of congenital heart diseases [2]. The gene discussed is MUC5AC; the disease is cystic fibrosis.