ScRNA-seq analyses identified endothelial-afferent/efferent arterioles/descending vasa recta (AEAs/DVR) as the key cell, with ATF3 expression primarily detected during the early stage of AEAs/DVR differentiation.<h4>Conclusion</h4>ATF3 was found downregulated in many cancers and proposed as a pan-cancer biomarker; in KIRC, its low level predicted poor outcome, indicating a potential immunotherapy target. Here, ATF3 is linked to cancer.