Interpret stacked violin plots

Question

[melissachua90]

I have a stacked violin plot from a single-cell RNA dataset and I'm not sure how to interpret.

Am I correct to say that: (1) The subplots facing upwards infer upregulation of gene expression (2) the subplots facing downwards infer downregulation of gene expression

[rpolicastro]

Since there are no axis or figure legend we can only guess, but it's probably violin plots for the expression of each gene in each cluster. Generally the higher the "mass" is on the y-axis the more cells there are expressing the gene at higher levels in that cluster. Think of the violin plots as sideways histograms. The fill color for the violin plots is the median expression for that gene in each cluster.

[jv]

I agree, this doesn't appear to be visualizing differential expression results. The color legend is labeled 'Median expression in group'. Most likely visualizing the distribution of reads per cell in the cluster for the gene on the x-axis.