HTR1B and major depressive disorder: Specifically, the palmitoylation of 5-HT1B [96], 5-HT4 [97], and 5-HT7 [98] may be associated with the development of anxiety and depression due to their roles in physiological and pathophysiological responses, and the palmitoylation of 5-HT1A receptors may be of the most importance since it is irreversible and insensitive to agonist stimulation [99].