1) With stomach cancer tissue obtained from 15 cancer-bearing patients, either immediately frozen as it is at 40℃ and preserved, or fixed in 5% formalin solution and stored for one week at 4℃ as the starting materials, antigen was extracted by fluorocarbon treatment. With the antigen so obtained the skin reaction was observed by intradermal injection of the antigen. As the result it was found that there was no significant difference in the skin reaction between cancer-bearing patients and non-cancer bearing group. 2) When intraperitoneal lymphoid cells from the patient (donor) showing positive skin reaction to this fluorocarbon extracted antigen were transplanted to the patient (recipient) showing negative skin reaction to the antigen, the recipient turned positive to the antigen. In other words, there was established passive transfer. 3) When the sediment obtained by centrifugation at 100,000 g of the tumor tissue of stomach cancer patient was injected to the same patient, there could be observed delayed type of allergic skin reaction in 8 out of 10 patients. Even with similar injection of the supernatant fraction of the stomach cancer tissue after the centrifugation (delayed allergic). 4) After the intradermal injections of the sediment fraction obtained by centrifugation of methylcholanthrene-induced sarcoma (MC-induced) tissue at 100,000 g to MC-sarcoma-bearing animals, there was observed induration in 8 out of 10 animals injected with the sediment fraction, whereas it was seen in 6 out of ten animals injected with the supernatant fraction. Histological picture of these animals revealed delayed allergic reaction, indicating the coexistence of immediate type reaction.