AbstractThe anticancer drug netropsin increases the synthesis of an exocellular metalloproteinase during exponential growth as well as in the stationary phase of a sporulating strain ofBacillus megaterium. Its effect is due to a stimulation of the synthesis of the mRNA coding for the proteinase, determined as a residual synthesis of the enzyme in the presence of actinomycin D. The half‐life of the proteinase mRNA (5–6 min at 35 °C) is not affected by netropsin. Netropsin relieves partially the repression of the proteinase mRNA caused by amino acids, whereas the repression brought about by an increased temperature is almost unaffected by the