This dissertation is concerned with the review of my research activity
starting from the PhD at the Politecnico of Turin to my research activity
at ENS of Paris. The research activity has been mainly concerned with the
development and analysis of models for the description of complex systems,
especially biological systems, vehicular traffic, crowds dynamics,
economic systems, by means of the thermostatted kinetic theory for active
particles. By employing mathematical and physical tools, different types
of dynamics have been investigated including tumor-immune system
competition and the onset of hyperbolic and parabolic behaviors at the
macroscopic scale. Finally I will present further developments of this
theory and its applications to cancer.