Controlling cancer by medical treatment depends on the tumor nature but also by the ability of our immune system to recognize and control tumor growth. We identified one important mechanism used by tumor to weaken immune defense involving a particular type of immunosuppressive cells (the myeloid cells), and most importantly we have found a test (the Myeloid Index Score, or MIS) to measure this weakness by a simple blood test. In the Serpentine proposal, thanks to the join-effort of different cancer centers in Europe and abroad, we are committed to prove that MIS might help individualize those cancer patients whose immune system suffers of such a weakness and to demonstrate that these patients would need more intensive treatment regimens to obtain disease control. We are also going to study and possibly discover strategies to counteract myeloid-mediated immunosuppression in order to help improving cancer therapy at patient-tailored level.