Pulmonary lymphangioleiomyomatosis (LAM) is a rare respiratory disease that occurs only in women, with an average age of onset of 30-40 years. Patients can present with dyspnea, pneumothorax, and celiac disease, which severely affect their respiratory function. In 2000, the pathogenesis of LAM was revealed to be due to a mutation in the TSC2 gene resulting in excessive activation of mTOR, a key molecule that controls cell growth. Rapamycin was considered the most promising therapeutic agent due to its ability to specifically inhibit mTOR. Since then, scientists and LAM patient groups have been scrambling together on a quest to find out whether rapamycin actually works. In 2003, after the TSC mutation mechanism was further confirmed to co-exist in LAM and tuberous sclerosis, the first small-scale clinical trial was initiated. Before the study was formally published, the clinical study protocol of rapamycin for the treatment of LAM (MILES) was submitted for discussion in 2005 after preliminary valid study data were obtained, and the enrollment of patients officially started at the end of 2006. The study was completed in August 2010. The MILES study was published in the March 16, 2011, online edition of the New England Journal of Medicine and confirmed the effectiveness of rapamycin in treating LAM. This article provides an introduction to it. The full text of the study can be found in the original article (www.nejm.org). The main results of the study The MILES study was a randomized, double-blind, placebo-controlled clinical study that included 89 patients with LAM in two phases, with a 12-month double-blind period in the first phase and a 12-month discontinuation period for observation in the second phase. The primary observation was the rate of change in first-second forceful expiratory volume (FEV1). During the treatment phase, FEV1 decreased by a mean of 12±2 ml per month in the placebo control group and increased by 1±2 ml per month in the rapamycin-treated group. the difference was significant, suggesting that rapamycin stabilizes pulmonary function in patients with LAM. over 12 months, the mean improvement in FEV1 in the rapamycin-treated group was 153 ml higher than in the control group, corresponding to 11% of pulmonary function at entry . In terms of other pulmonary function indicators, rapamycin treatment was effective in improving forceful expiratory volume (FVC) and functional residual air volume. Also rapamycin may have improved patient quality of life and reduced serum VEGF-D levels. Pulmonary diffusion function and 6-minute walk distance were not improved. The therapeutic effect fades away after discontinuation of rapamycin. In terms of adverse effects, rapamycin treatment brought about more adverse effects, but no increase in serious adverse effects. The results of the study showed that rapamycin stabilized lung function, reduced serum levels of VEGF-D, reduced patient symptoms and improved patient quality of life. Rapamycin has the potential to be therapeutically effective in selected patients. In addition to funding from U.S. government funds and Pfizer (formerly Wyeth Pharmaceuticals now incorporated into Pfizer), the MILES study was supported by two patient organizations, the LAM Foundation and the TSC Alliance. The New England Journal of Medicine published an editorial on “Patient groups and rare disease research” in the same issue. The article praised the active role of patient organizations in rare disease research. Indeed, LAM research has been driven by patient groups in a way that is faster, better, and stronger than other diseases. When I think back to 15 years ago, the medical community could be said to know nothing about LAM. Originating from the mother of a LAM patient, a music teacher who did not know anything about medicine, the LAM Foundation of America was founded. The success of LAM is not only limited to LAM, but also inspiring and exemplary to other rare disease research.