CXCL13 and neoplasm: DNA and RNA were isolated from patient tumor biopsies and characterized using NGS. Interrogated CXCL13 expression and ARID1A mutation as a combination biomarker in predicting response to ICT in CheckMate275 and IMvigor210. The combination of the two biomarkers in baseline tumor tissues suggested improved OS compared to either single biomarker. Cumulatively, this study revealed that the combination of CXCL13 plus ARID1A may improve prediction capability for patients receiving ICT.