Normalization of single-cell RNA-seq counts by log (x+ 1) or log (1+ x)

Differences in ACE2 mRNA abundance were proposed to influence COVID-19 severity. ACE2 estimates from single-cell RNA-seq commonly use filtered, normalized counts, yet conditioning on nonzero counts and applying log1p distort expectations for lowly expressed genes. These choices made a reported ACE2 comparison misleading and have contributed to misleading published results.