Pre-HCT pulmonary metatranscriptome clusters. Four distinct clusters of BALF samples were identified based on combined microbiome and gene expression data therein. (A) Hierarchical clustering of UMAP coordinates identified 4 groups of patient samples. Centered scaled total respiratory viral RNA mass (B) and total bacterial RNA mass (C) are overlaid on sample coordinates to demonstrate how microbiome characteristics vary across clusters. x̃_Cn indicates the median mass of total respiratory viral RNA (B) or total bacteria (C) within each pulmonary metatranscriptome cluster.