In line with the scRNA-seq data, we further validated the spatial distribution features of the two PCs, with significant more IgG+CD138+ PCs, but not IgA+CD138+ PCs in the imatinib sensitive GIST, compared with those in the imatinib resistance GIST tumor tissues (Figure 3F-G). This evidence concerns the gene SDC1 and gastrointestinal stromal tumor.