CCL4 and neoplasm: Likewise, an unbiased gene expression analysis to identify the top 50 variable genes in our tumor/tumoroid data set followed by hierarchical clustering illustrated a decrease in gene expression levels associated with immune and stromal cells (e.g., CCL3, CCL4, COL1A2, COL1A3) when comparing tumors and derived tumoroids (Supplementary Fig. S3).