Abstract Objective: Cannabinoids are a class of compounds that have the ability to activate two specific receptor subtypes, the cannabinoid CB1 and CB2 receptors. CB1 receptor is a G-protein-coupled receptor that is linked to the signal transduction pathways. The cumulative effects of this receptor have important implications in the control of cell survival and cell death having the potential to regulate tumor cell growth. In this connection, interest has been focused on factors such as sex steroid hormones, which regulate CB1 receptor expression. The aim of this study was to investigate the effects of 17beta-estradiol exposure on the CB1 receptor gene and its protein expression...