“…Hegu (LI 4) (9 studies) ( Zeng et al, 2006 ; Dougherty et al, 2008 ; Kong et al, 2009a , b ; Zyloney et al, 2010 ; Jiang et al, 2014 ; Theysohn et al, 2014 ; Lee et al, 2015 ; Niu et al, 2017 , Zusanli (ST 36) (8 studies) ( Weiting et al, 2003 ; Zhang et al, 2003a , b ; LaMei et al, 2013a , b ; Theysohn et al, 2014 ; Lin et al, 2018 ; Wenjin et al, 2020 , and Sanyinjiao (SP 6) (4 studies) ( Weiting et al, 2003 ; Zhang et al, 2003a , b ; Cao et al, 2019 ( Supplementary Table 4 ) were the most used acupoint selection in these 27 studies. The aforementioned acupoints were widely used for pain relief in the clinic ( Zeng et al, 2009 ; Fofi et al, 2014 ; Wang et al, 2015 . Besides, the acupoints were located on the four limbs which were commonly used because they were easy to perform acupuncture manipulation during the scanning.…”