CD44 and cancer: We could give some examples of antigens that could be targeted in such a way: CD44 (1) (surface cell protein which have 10 different juxtamembranous isoforms—some of them are reported to be present only on specific cancer cells) [14], PSMA (2) (Prostate Specific Membrane Antigen) [117], N-cadherin (3) [118], mesothelin (4), or mHSP70 (5).