Vinorelbine ditartrate is a selective mitotic microtubule antagonist that exhibits > 20 fold selectivity over axonal microtubules. This compound has been shown to inhibit the proliferation of multiple human tumor cell lines (IC50 = 1.25 nM in HeLa cells). Vinorelbine ditartrate is a selective mitotic microtubule antagonist that exhibits > 20 fold selectivity over axonal microtubules. This compound has been shown to inhibit the proliferation of multiple human tumor cell lines (IC50 = 1.25 nM in HeLa cells).