Some of my not so favorite things about insulin and insulin-like growth factors in fish.

Several topics concerning insulin and IGFs rarely discussed among comparative physiologists/endocrinologists are reviewed. The topics addressed include interpretation of radioimmunoassays for insulin and IGFs, the major sites of synthesis of these peptides, signal transduction via peptide-specific, and possibly via related peptide receptors. Finally, some thoughts are included on the development of the insulin superfamily of peptides in two phyletic lines of evolution, proto- and deuterostomian animals. The author considers all the above topics open to further exploration. If this review initiates more discussion leading to unorthodox input to the field, its goal is achieved.