Figure 3.

Spurious gene-gene correlation caused by data oversmoothing

Scatterplot of expression values of non-associated gene pair, OGT and MB21D1, preprocessed by different methods. There is no existing evidence to indicate that these two genes are correlated, and only 3 out of 6,534 cells in cluster #2 had non-zero expression value in both genes in the original expression matrix. However, after preprocessing, NBR, DCA, and MAGIC all produced high correlations (0.843, 0.828, and 0.739) and high mutual information (2.1, 0.72, and 0.663 nat) between these two genes. The visualization suggested that this correlation artifact may be caused by data oversmoothing.