CEACAM5 and neoplasm: We detected the following interactions between complex tumor markers: CEA x TPA, ferritin (FT)/serum iron(Fe), CEA x TPA/FT/Fe, alpha‐1‐globulin fraction(alpha‐1) x (alpha‐2‐glubulin: alpha‐2), and (alpha‐1) x TPA 2, 3.