St. Mary’s Hospital and the Isotope and Nuclear Chemistry Division of the Medical Radioisotopes Research Program at Los Alamos National Laboratory conducted preliminary studies from 1988 to 1992 researching porphyrins that led to more specific research into 10,15,20-tetrakis (4-carboxyphenyl) porphine (TCPP) and its ability to detect lung cancer by labeling cancer cells in sputum.