TGFB1 and chronic obstructive pulmonary disease: Therefore, exploration of other pathways must be developed to understand the role of Pneumocystis as a co-factor in the increment of the severity of COPD, and thus, in this work, we documented the role of other pathways, such as IL1β and TGFβ1, which have been proposed as key factors and have a potential contribution to the increment of the severity of the disease in these infected animals.