CTSL and retinoblastoma: However, ZEB1 (FC = 77.2, p < 0.05), SNAI2 (FC = 3.32, p < 0.05), ABCB1 (FC = 4.4, p < 0.05), and CTSL (FC = −3.8, p < 0.05) expressions were significantly downregulated in non-advanced Rb tumors.