Asthma from immune pathogenesis to precision medicine

•Asthma is a multifaceted heterogeneous syndrome that is the result of various inflammatory pathways.•Both innate and adaptive immune systems, together with epithelial cells, are involved in the pathogenesis of asthma.•Eosinophilic (allergic or non allergic) endotypes are the most common inflammatory presentations of asthma.•Neutrophilic and paucigranular endotypes are also described.•The identification of asthma endotypes is the pre-requisite for choosing the proper biological drug for the right patient. Asthma is characterized by multiple immunological mechanisms (endotypes) determining variable clinical presentations (phenotypes). The identification of endotypic mechanisms is crucial to better characterize patients and to identify tailored therapeutic approaches with novel biological agents targeting specific immunological pathways. This review focused on summarizing the major immunological mechanisms involved in the pathogenesis of asthma, as well as on discussing the emergence of phenotypic features of the disease. Novel biological agents and other drugs targeting specific endotypes are discussed, as their use represent a precision medicine approach to the disease that is nowadays mandatory particularly for treating more severe patients.