Volume 40 of "Progress in Drug Research" contains six reviews and the various indexes which facilitate its use and establish the connec­ tion with the previous volumes. The articles in this volume deal with phosphodiesterase inhibitors and their therapeutic potential in asthma; peptide receptor ligand drugs; aldose reductase inhibitors; the design and discovery of new drugs by stepping-down and stepping-up approaches; new synthetic ligands for L-type voltage­ gated calcium channels and with luteolytic agents in fertility regula­ tion. III the 33 years that "Progress in Drug Research" has existed, the Edi­ tor has enjoyed the valuable help and advice of many colleagues. Readers, the authors of the reviews, and last but not least, the review­ ers have all contributed greatly to the success of this series. Although the comments received so far have generally been favorable, it is nevertheless necessary to analyze and to reassess the current position and the future direction of such a review series.