EPSTI1 and systemic lupus erythematosus: 15. Recent studies have shown that EPSTI1 is highly increased in patients having inflammatory diseases (systemic lupus erythematosus, lymphadenitis, and COVID-19) or cancers 16-19. Although the molecular function of Epsti1 has rarely been investigated, a study suggested that Epsti1 can interact with valosin-containing protein (VCP), facilitating ubiquitin-proteasome-dependent protein degradation 20.