TMEM59L (transmembrane protein 59 like) is a neuron-specific transmembrane protein that localizes to the Golgi apparatus and endosomes, with primary functions in cellular stress response and cancer progression 1. The protein mediates oxidative stress-induced cell death through caspase-dependent apoptosis and interacts with autophagy regulators ATG5 and ATG16L1 1. TMEM59L exhibits pro-apoptotic properties and its downregulation protects neurons against oxidative stress, improving behavioral outcomes related to anxiety, depression, and memory in mouse models 1. In cancer contexts, TMEM59L demonstrates complex roles across different tumor types. It shows differential expression patterns, being downregulated in colorectal adenocarcinoma tissues but elevated in serum samples, where high expression correlates with advanced tumor stage and poor prognosis 2. The protein promotes epithelial-mesenchymal transition (EMT) and enhances cellular proliferation, migration, and invasion 2. Additionally, TMEM59L contributes to chemotherapy resistance by regulating DNA damage repair mechanisms, particularly through PTPRN-mediated pathways that enhance 5-fluorouracil resistance in colorectal cancer 3. The protein also influences radiotherapy sensitivity in glioblastoma through modulation of DNA damage repair and oxidative stress response processes 4.