Figure 3: Description of the steps involved in production of therapeutic DCs. Step 1 involves leukapheresis followed by selection of precursor DC. In Step 2, precursor DC is cultured in vitro under the influence of cytokines where they transform into immature DC. In Step 3, they are exposed to the tumor Ag, which helps them transform into mature DC. In Step 4, these mature DC (capable of fighting cancer cells) are transfused back into the patient. DC: Dendritic cell