Abstract: The present invention provides a gene Any-RF derived from an insect, having dormancy-control activity and biological cell-control function; a dormancy-control substance and a method for preparing the same; as well as a biological cell-control agent, which comprises, as an effective component, a physiologically active substance having a biological cell-control function and which never causes any antigen-antibody reaction in the living body. The gene encodes for a protein having an amino acid sequence specified as Sequence No. 1 in SEQUENCE LISTING: Asp-Ile-Leu-Arg-Gly, whose C-terminal is amidated and having a molecular weight of 570.959. The physiologically active substance comprising such a gene is a peptide, which can be isolated and purified by adding an acid-methanol aqueous solution to Antheraea yamamai, triturating the resulting mixture, centrifuging the same and then treating the resulting supernatant in an HPLC system.