Recently, we and others reported retrospective data which suggest that either an early addition of immunosuppressive drugs to glucocorticoids or the combined use of glucocorticoids and immunosuppressive drugs from the initial treatment may improve the survival of PM/DM patients. To save lives of PM/DM-IP patients, desperate treating physicians have started using this approach, strongly urging the conduct of prospective studies to investigate the superiority of this approach over glucocorticoids alone. At the same time, it was considered not ethically appropriate to conduct a prospective study with a concurrent controlled group receiving glucocorticoids alone given the presence of the PM/DM-IP subtype with rapidly progressive course and high short-term mortality if treated with glucocorticoids alone and the absence of useful demographic or bio-markers which could distinguish patients with this subtype early. Among immunosuppressive drugs used in the treatment of PM/DM-IP, tacrolimus has recently been suggested to be effective even for those patients who are resistant to cyclosporine or cyclosphosphamide.