Abstract: This disclosure is directed to a pharmaceutical composition comprises tumor inhibiting cells (TICs) and a method for producing the TICs. The tumor inhibiting cells can be derived from immune cells including T cells, NK cells, or a combination thereof, modified to have inactivated Cbl-b gene alleles and free from Cbl-b bio-function (Cbl-b?/? TICs). The Cbl-b?/? TICs are free from deoxyribonucleic acids exogenous to the immune cells. The immune cells can be isolated using a portable cell isolation and modification device. This disclosure is further directed to a method for treating tumorous conditions in subjects. The pharmaceutical composition can provide a subject-specific tumor treatment.