APIP (APAF1 interacting protein) functions as a methylthioribulose-1-phosphate dehydratase in the methionine salvage pathway, catalyzing the conversion of methylthioribulose-1-phosphate to 2,3-diketo-5-methylthiopentyl-1-phosphate 1. The protein plays critical roles in inflammation regulation by binding to TRAF6 and activating NF-κB and JNK signaling pathways, thereby facilitating priming of both canonical NLRP3 and non-canonical caspase-11/4 inflammasomes 2. In cancer contexts, APIP is transcriptionally activated by YAP and promotes head and neck squamous cell carcinoma metastasis through methionine cycle enhancement, leading to GSK3β phosphorylation and epithelial-mesenchymal transition 1. APIP also demonstrates cardioprotective functions by binding to and stabilizing adenosine receptor A2B (ADORA2B), activating PKA-CREB signaling pathways during myocardial infarction 3. Additionally, APIP promotes prostate cancer cell proliferation and migration via ERK1/2 pathway activation, with its expression negatively regulated by microRNA-146a-3p 4. Clinically, APIP expression correlates with disease severity in various conditions and represents a potential therapeutic target for inflammatory diseases and cancer metastasis.