The first clinically utilized XPO1 inhibitor (XPO1i) is the anti-tumour Streptomyces antibiotic leptomycin B (LMB), which is a natural XPO1i that covalently attaches to the cargo binding pocket of XPO1 to potently inhibit its interaction with cargo proteins [18]. This evidence concerns the gene XPO1 and neoplasm.