SERPINE1 and neoplasm: Recently, conditional Bmal1 knockout mice that lacked the BMAL1 protein during adult life experience different phenotypes relative to those of conventional Bmal1 knockout mice.[55] An unexpected signaling pathway of the Bmal1KO‐PAI‐1‐tPA/uPA‐plasmin‐TGF‐β‐fibrosis axis has been discovered as a key regulatory loop in controlling tumor growth and metastasis.