【終於.......】評論
Based on differences in their envelope glycoproteins, ALVs are divided into six subgroups (A, B, C, D, E, and J). Subgroup A (ALV-A), B, C, D and J (ALV-J) are considered exogenous, whereas subgroup E encompasses the endogenous viruses. 參考：張書維(2010)台灣土雞與蛋雞家禽白血病之病毒分離、序列分析及流行病學調查