Interestingly, despite previous study indicated Relish increased the pirk expression level during Gram-negative bacterial infection [58], our result showed Relish overexpression in Drosophila fat bodies decreased pirk expression under starvation (Supplementary Figure 3C), which might explain why BubR1 deficiency suppressed Relish mRNA level and increased pirk expression upon fasting at the same time. Here, BUB1B is linked to gram-negative bacterial infections.