In the past decades, new insights into molecular mechanisms of severe asthma have further unveiled its heterogeneous nature prompting the need for personalised and targeted approaches. These and several other hot topics related to severe asthma were addressed in the 4th International Severe Asthma Forum, organized by the Asthma, ENT, Immunology and Pediatric sections of the European Academy of Allergy and Clinical Immunology in collaboration with the Spanish Society for Allergy and Clinical Immunology.