This special issue is a tribute to our mentor, colleague and friend, Gavril W. Pasternak, MD, PhD. Homage to the breadth and depth of his work (~ 450 publications) over a 40 career in pharmacology and medicine cannot be captured fully in one special issue, but the 22 papers collected herein represent seven of the topics near and dear to Gav’s heart, and the colleagues, friends and mentees who held him near to theirs. The seven themes include: (1) sites and mechanisms of opioid actions in vivo; (2) development of novel analgesic agents; (3) opioid tolerance, withdrawal and addiction: mechanisms and treatment; (4) opioid receptor splice variants; (5) novel research tools and approaches; (6) receptor signaling and crosstalk in vitro; and (7) mentorship. This introduction to the issue summarizes contributions and includes formal and personal remembrances of Gav that illustrate his personality, warmth, and dedication to making a difference in patient care and people’s lives.

本期特刊是对我们的导师、同事和朋友 Gavril W. Pasternak 医学博士和博士的致敬。对他在药理学和医学领域 40 多年的工作（约 450 篇出版物）的广度和深度表示敬意，不能在一个特刊中完全体现出来，但本文收集的 22 篇论文代表了 Gav 心中的七个主题，以及把他抱在身边的同事、朋友和学员。这七个主题包括：（1）体内阿片类药物作用的部位和机制；(2) 新型镇痛剂的开发；(3) 阿片类药物耐受、戒断和成瘾：机制和治疗；(4) 阿片受体剪接变体；(5) 新颖的研究工具和方法；(6) 体外受体信号和串扰；(7) 指导。