I have run a bulk RNA-seq for 4 tissue samples. Each sample contains 50 cells collected from FACS, but due to technical challenges, my cells of interest account for varying proportions of those 50 cells across the 4 preps. Are there any functions in DESeq2 or other packages to uncover genes that are expressed in my cells of interest even though the samples were a mixture of cell types? My cells are labeled by tdTomato, so I do have counts for tdTomato transcripts. One thought is to find genes that would correlate with tdTomato expression. Is this reasonable? If so, what would be a good way to look for correlated genes in the whole dataset? Clustered heatmap seems to work best for selected set of genes?