This section of the article provides a list of references and acknowledgments. The references cover various studies on the crystal structures of protein complexes, including human growth hormone and its receptor, interferon-γ and its soluble high-affinity receptor, EPO receptor complex, interleukin-1 receptor complex, and others. The acknowledgments thank J. A. Malakaya, T. Pelton, and A. Bateman for their contributions. The section also includes an erratum for a previous publication and a copyright notice emphasizing the importance of obtaining proper permissions for photocopying.This section of the article provides a list of references and acknowledgments. The references cover various studies on the crystal structures of protein complexes, including human growth hormone and its receptor, interferon-γ and its soluble high-affinity receptor, EPO receptor complex, interleukin-1 receptor complex, and others. The acknowledgments thank J. A. Malakaya, T. Pelton, and A. Bateman for their contributions. The section also includes an erratum for a previous publication and a copyright notice emphasizing the importance of obtaining proper permissions for photocopying.