Most of the σ2 ligands not only show high affinity for the σ2 receptor but also exhibit excellent anti-tumor activity (Georgiadis et al., 2017; Sun et al., 2018; Liu et al., 2019), and those with a 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline structure could also interact with ABCB1 (Pati et al., 2015). The gene discussed is ABCB1; the disease is neoplasm.