In other words, when the CXCR2/p21-dependent senescence pathway is interrupted (that is, the loss of expression of p21), the evasion of senescence may restore the metastatic potential of hPTTG1 overexpression, as strong staining of hPTTG1 and CXCR2 in metastatic carcinomas was observed (for example, Figure 7G, Patient 2). This evidence concerns the gene CXCR2 and metastatic carcinoma.