Have a question concerning cutoff for Venn Diagram generation. Comparing microglia model systems for expression of microglia signature and microglia-enriched genes. Would like to observe three group Venn diagrams between model systems, ie iPSC-microglia, monocyte-derived microglia and primary adult microglia. My specific question is how to determine cutoff from TPM data for positive expression of a given gene? Seems arbitrary, but are there specific statistical or accepted methods to identify cutoff? For example, a TPM cutoff of 50 will provide about a 10-12% positive identification from 38k complete genomic genes. From there the subset of genes will be restricted to 882 microglia genes.Thanks in advance.