“…To investigate the correlation between IDO1 expression and prognostic related laboratory test indexes, patients were divided into IDO1-high or IDO1-low group according to the average positive count of IDO1 in their tumor tissues. Additionally, laboratory test indexes at diagnosis of these OS patients were collected ( Table 1 ), including serum alkaline phosphatase (ALP) ( Hao et al, 2017 ; Bao et al, 2019 ), lactate dehydrogenase (LDH) ( Fu et al, 2018 ), white blood cell (WBC) count ( Viola et al, 2021 ) and C-reactive protein (CRP) ( Jettoo et al, 2019 ), as they are prognostic factors for OS reported in multiple studies. We found that between IDO1-high and IDO1-low groups, serum ALP and LDH concentrations showed significant difference, while WBC and CRP level did not ( Figures 2A–D ).…”