SIGMAR1 and cancer: Until recently, for Sigma1, this association was largely based on two lines of evidence: (Martin et al., 1976) elevated expression of SIGMAR1 transcripts and Sigma1 protein, primarily in cancer cell lines and some tumors (Kim and Maher, 2017) and (Su, 1982) antiproliferative and apoptosis inducing effects of some small-molecule inhibitors (putative antagonists) of Sigma1 on cancer cell lines (reviewed extensively in (Kim and Maher, 2017) and briefly outlined in Table 1).