By contrast, analysis of different tumor samples revealed the absence of γc chain staining (P<0.01) with a very faint JAK3 protein expression (P<0.01) while, no significant differences (P>0.05) in the expression of the IL-2Rβ chain were observed between normal and tumoral tissues therefore confirming the results obtained in vitro in primary cultures of normal and cancer cells. This evidence concerns the gene IL2RB and cancer.