ALK and renal cell carcinoma: Among them, they can be roughly divided into two categories according to the morphology: One is ALK-rearranged RCC with VCL as a fusion gene, which occurs mostly in childhood and has a sickle-cell trait, eosinophilic granulocytic stroma, and cytoplasmic lumen [69,71]; the other category comprises other ALK-rearranged RCCs, most of which have a morphology similar to PRCC and also consist of abundant intracellular and extracellular mucins with eosinophilic granuloplasm [67,69].