Factors Linked to Frequent Attendance in the Out-of-hospital Setting by Patients With Chronic Obstructive Pulmonary Disease María Estrella López-Pardo, Cristina Candal-Pedreira, Luis Valdés-Cuadrado, Cristina Represas-Represas, Alberto Ruano-Ravina, Mónica Pérez-Ríos

Immune Gene Polymorphisms and Lung Cancer Risk in Chronic Obstructive Pulmonary Disease with Emphysema Paola Ordóñez Gómez, María Dolores Miñana, Carlos García-Ballesteros, Jaime Signes-Costa, Juan José Soler-Cataluña

Core Microbiota in Central Lung Cancer With Streptococcal Enrichment as a Possible Diagnostic Marker Salvador Bello, José J. Vengoechea, Manuel Ponce-Alonso, Ana L. Figueredo, Elisa Mincholé, Antonio Rezusta, Paula Gambó, Juan Manuel Pastor, Javier Galeano, Rosa del Campo