In the last four decades, tumor immunology has shed light
on identity and functions of cells and molecules involved
in tumor rejection through the involvement of the immune
system [1]. Several groups of immune cells have been
demonstrated to be able to contrast tumor occurrence and
tumor progression by killing immunogenic tumor cells, a
phenomenon recognized under the definition of “immunosurveillance” [2]. Unfortunately, cancer may evade immunosurveillance and progress through the modifications of its
own antigens, which can reduce tumor immunogenicity
and/or increase its immunosuppressive action [3]. After years
of investigations, harnessing the immune system to attack
cancer has recently led scientists to gather enough clinical
data to show what a powerful sword immunotherapy can
be
