Cover picture: The structure of the active site of a triple mutant of sperm whale myoglobin. The electron density map of the oxy (white) and deoxy (red) derivatives clearly shows on the left the proximal His(F8) and on the right two mutated distal residues, Tyr(B10) and Gln(E7), as well as bound oxygen. See the article by Brunori et al. on p. 1259.