IFNL4 genetic variant can predispose to COVID-19.

Interferon lambda 4 (IFNλ4) has shown antiviral activity against RNA viruses, including some coronaviruses. Besides, genetic variants of IFNL4 can be predictive of the clearance of RNA viruses. However, little is known about the effect of these genetic variants on SARS-CoV-2 infection.

Proteolytic regulation of activated STAT6 by calpains.

The transcription factor STAT6 plays an important role in cell responses to IL-4. Its activation is tightly regulated. STAT6 phosphorylation is associated with JAKs, whereas dephosphorylation is associated with specific phosphatases.

Phosphatidylcholine-specific phospholipase C activity is necessary for the activation of STAT6.

It is well established that Janus kinase (JAK) tyrosine kinases play a key role in the activation of STAT6 by IL-4. In this study, we investigated additional molecules involved in this process. We previously found that IL-4 and TNF-alpha cooperate in the activation of STAT6 and NF-kappaB, suggesting that these transcription factors are regulated by common intracellular signaling pathways.