Similarly, reduced levels of pro-IL-1β protein were detected in the Syk KO cells compared to the EV control cells during infection (Fig 4D), suggesting that Syk functions upstream of IL-1β transcription and pro-IL-1β protein synthesis in THP-1 cells, similar to the effects of the R406 and entospletinib inhibitors in primary human monocytes. Here, SYK is linked to infection.