Objective The aim of this study was to investigate the prognostic relevance of acid phosphatase 1(ACP1) expression in myeloma patients by using Gene Expression Omnibus(GEO) datasets.Methods A comprehensive search was performed in the GEO database in order to find appropriate datasets. The expression level of ACP1 was extracted from the dataset involving both newly diagnosed and relapsed myeloma patients, and a comparison was made. Clinical follow-up data and ACP1 expression were extracted, and survival analysis of overall survival was performed to compare the high-(top quartile) and low-expression(bottom quartile) groups. Analyses using Kaplan-Meier estimation, log-rank test, and restricted mean survival time(RMST) comparison were performed.Results The GSE 6477 dataset was used to make a comparison of the ACP1 expression levels among patients with newly diagnosed and relapsed myeloma. The ACP1 expression level was significantly higher in the relapsed group than in the newly diagnosed group [mean difference =-262.9, 95% confidence interval(CI) =(-420.2,-105.5), P = 0.002]. The GSE 2658 dataset was used for investigating the prognostic relevance of ACP1 expression in myeloma. The ACP1 high-expression group had a significantly worse prognosis [low vs high: hazard ratio = 0.54, 95% CI =(0.31, 0.95); χ2 = 5.02, log rank P = 0.0314]. The median survival was 55.9 months in the high-expression group and was not reached in the low-expression group. The restricted mean time loss(95% CI) was 11.03(12.97, 23.11) and 18.04(12.97, 23.11) for the low-and high-expression groups, respectively. The ratio of RMST(95% CI) between the two groups(high vs low) was 0.87(0.77, 0.99; P = 0.03).Conclusion Our study, for the first time, showed that ACP1 predicts the prognosis in multiple myeloma patients. Further studies are needed to determine the potential mechanism by which ACP1 is associated with clinical outcomes and should focus on the differential roles of low-molecular-weight protein tyrosine phosphatase(LMWPTP) isoforms. Objective The aim of this study was to investigate the prognostic relevance of acid phosphatase 1 (ACP1) expression in myeloma patients by using Gene Expression Omnibus (GEO) datasets. Methods A comprehensive search was performed in the GEO database in order to find appropriate datasets. The expression level of ACP1 was extracted from the dataset involving both both previously diagnosed and relapsed myeloma patients, and a comparison was made. Clinical follow-up data and ACP1 expression were extracted, and survival analysis of overall survival was performed to compare the high- ( Analyzes using Kaplan-Meier estimation, log-rank test, and restricted mean survival time (RMST) comparison were performed. Results The GSE 6477 dataset was used to make a comparison of the ACP1 expression levels among patients with newly diagnosed and relapsed myeloma. The ACP1 expression level was significantly higher in the relapsed group than in the newly diagnosed g The GSE 2658 dataset was used for investigating the prognostic relevance of ACP1 expression in myeloma. The ACP1 high- The median survival was 55.9 months in the high-expression group (low vs high: hazard ratio = 0.54, 95% CI = (0.31, 0.95); χ2 = 5.02, log rank P = 0.0314] and was not reached in the low-expression group. The restricted mean time loss (95% CI) was 11.03 (12.97, 23.11) and 18.04 (12.97, 23.11) for the low-and high-expression groups, respectively. The ratio of Further studies are found in the two groups (high vs low) was 0.87 (0.77, 0.99; needed to determine the potential mechanism by which ACP1 is associated with clinical outcomes and should focus on the differential roles of low-molecular-weight protein tyrosine phosphatase (LMWPTP) isoforms.