An interesting abnormality encountered in many types of tumour is the synthesis of substance normally restricted to feta在许多类型肿瘤中出现一种使人关注的异常，是合成在正常情况下限于胎儿期形成的物质，例如成人肝细胞癌产生甲胎蛋白（在正常情况下，由胎儿肝细胞产生）。