Li X, Chen W, Li J, et al. - Researchers retrospectively recognized 565 patients with newly diagnosed multiple myeloma (NDMM) from multiple centers in China to examine the prognostic value of 1q21 gain in a Chinese population. In 222 patients 1q21 gain was discovered, among whom 144 had three copies of 1q21, 57 had four copies of 1q21, and 21 had at least five copies of 1q21. Any impact on the disease outcome was not exhibited by copy number variation. Multivariate analysis revealed that 1q21 gain was an independent factor for poor prognosis, although, 1q21 gain was strongly related to other high-risk factors, like del(17p), t(4;14), t(14;16), lactate dehydrogenase (LDH) level > 300 U/L and International Scoring System (ISS) stage II-III. In the absence of other high-risk factors, isolated 1q21 gain led to comparable progression-free survival (PFS) and OS and, moreover, when present with other high-risk cytogenetic abnormalities or increased LDH levels, 1q21 gain lost its prognostic power. Nonetheless, the adverse effect of the ISS stage was raised by the presence of 1q21 gain. Besides, in patients who received bortezomib-based regimens, 1q21 gain prognosticated poor PFS and OS. Further, in patients with 1q21 gain, autologous stem cell transplantation reversed the poor prognosis. Therefore, among patients with 1q21 gain, it was exhibited that heterogeneity exists and recommends that the effect of 1q21 gain on prognosis should be evaluated according to various treatment regimens and simultaneous with high-risk factors.