Fig 1: Multiplexed proteomic profiling of PCs.a Heatmap representation of CD138+CD38+ PC expression levels for the 14 selected biomarkers (refer to Table 2). Expression levels are depicted using values normalized to a 0–1 scale, which standardizes the different biomarkers for comparison by transforming their expression levels to a common scale. b Correlation matrix of CD138+CD38+ PCs from all samples for the selected 14 proteomic markers. Pearson’s correlation was used, and hierarchical cluster analysis was conducted. c Bar plot comparing the selected proteomic markers between precursor PCs (from MGUS samples) and disease PCs (from NDMM/RRMM/PCL samples). The Kruskal–Wallis H test (one-way ANOVA) was performed, and p-values below *0.05 were considered statistically significant.