Renal cell carcinoma nephroblastoma

A histological specimen of clear cell type of renal cell carcinoma appears characteristically as cuboidal cell with abundant clear, vacuolated cytoplasm and small nuclei. What accounts for the distinguishing histologic appearance of clear cell type of renal cell carcinoma?

1: Abundance of misfolded proteins within the cell cytoplasm
2: Apoptosis of malignant cells due to rapid turnover of cells
3: Lipid and glycogen accumulation within cells
4: Lipid peroxidation of cellular membranes