For example, 88 PEIs were correlated with the cytokeratin-19-fragment CYFRA21-1 (CYFRA 21-1); 83 PEIs were correlated with tumor-supplied group factors; 64 PEIs were correlated with neuron-specific enolase; and 64 PEIs were correlated with complex prostate-specific antigen (C-PSA) (Figs. 1 and 2, Table S1). The gene discussed is ENO2; the disease is neoplasm.