N-Desmethyltamoxifen, the principal metabolite of tamoxifen in humans, serves as an efficacious modulator of ceramide metabolism within human AML cells by inhibiting ceramide glycosylation, hydrolysis, and sphingosine phosphorylation. Although it demonstrates weak antiestrogenic properties, it acts as a protein kinase C (PKC) inhibitor with a potency ten times greater than that of tamoxifen.