1. A method of preparing an animal tumor model system comprising: e. preparing adhesion deprived cells by trypsinizing normal adherent rat fibroblast cells, F111; f. suspending the said adhesion deprived rat fibroblast cells (F111) of step ‘a’ on 0.8 to 1% agarose coated surface in Dulbecco's Modified Eagle's medium containing 8 to 10% Foetal Calf Serum (FCS) to obtain adhesion deprived transformed fibroblast cells; g. administering subcutaneously the said transformed adhesion deprived cells of step ‘b’ into an immunocompromised mammal; and h. glowing the adhesion deprived cells of step ‘c’ to metastasize in the immunocompromised mammal for a period of about 4 weeks to about 6 weeks after in vivo transformation to obtain the animal tumor model system.