CXCL8 and neoplasm: Tryptophan metabolizing enzymes can accelerate tumor progression by upregulating CXCL8 (Zhao et al., 2021), which is also a chemokine in the IL-17 signaling pathway, and CXCL8 has a high degree value in PPI network; hence, we speculate that CXCL8 could be a potential target in the treatment of PitNETs.