DHFR and cancer: A level of reduction of 0.1 from 2.2 to 2.1 of denaturated DHFR and 1.2 to 1 of the native DHFR is observed with inhibitory constants of 2.25 μM, 1.1 μM, and 8.63 μM for 4-benzoic acid-diphenyl-phosphene gold(I) chloride, 2-benzoic acid-diphenyl-phosphane gold(I) chloride, and 4,5-dichloroimidazolato-N-triphenylphosphine–gold(I), respectively, extending the use of the gold(I) compounds to the treatment of inflammatory infections, pneumonia, E. coli, and cancer.