Considering the concept that STAT3 can be an oncoprotein or a tumor suppressor (as described in Section 3), and that STAT3β functions as a dominant negative factor for STAT3α (as described in Section 4), it is highly possible that the expression of STAT3 and/pSTAT3 in tumor samples may correlate with the clinical outcome in either direction, depending on the genetic background of the tumor cells and/or the coexisting biochemical defects present in these cells, and whether the tumor suppressor effects of STAT3β overcomes the oncogenic effects of STAT3α. This evidence concerns the gene STAT3 and neoplasm.