In contrast to healthy tissues, a dramatic increase in polyamine levels is observed within cancerous tissues, as the activity of the rate-limiting enzyme for polyamine synthesis (i.e., ornithine decarboxylase) is upregulated by several oncogenic factors, including MYC family (regulatory gene and proto-oncogene).142 This allows the tumor cells to increase the uptake of polyamine from their microenvironment and thereby promotes tumor survival mechanisms by suppressing tumor-specific immune responses. The gene discussed is ODC1; the disease is neoplasm.