Based on the available literature, APCDD1L (APC down-regulated 1 like) appears to function primarily through its associated antisense long non-coding RNA (APCDD1L-AS1) rather than as a protein-coding gene itself. The antisense transcript APCDD1L-AS1 demonstrates context-dependent oncogenic or tumor suppressive roles across different cancer types 123. In lung adenocarcinoma, APCDD1L-AS1 promotes osimertinib resistance by stabilizing DLST protein and driving the tricarboxylic acid cycle, with its expression regulated by hypoxia-inducible factor HIF-1α 1. Conversely, in clear cell renal cell carcinoma, APCDD1L-AS1 functions as a tumor suppressor, with its downregulation due to DNA hypermethylation and VHL protein loss promoting cancer progression 2. The lncRNA also confers chemotherapy resistance in oral squamous cell carcinoma through exosomal transfer and miR-1224-5p/NSD2 axis regulation 3. Additionally, APCDD1L methylation changes have been identified in the nucleus accumbens of smokers, suggesting potential roles in addiction-related epigenetic modifications 4. The gene serves as a prognostic biomarker in multiple cancer types, though its specific protein function remains unclear from current literature 56.