GREM1 and acute lymphoblastic leukemia: There was no expression of PIG-2 in promyelocytic leukemia cell line HL-60, human cervical cancer cell line HeLa, chronic myelogenous leukemia cell line K-562, lymphoblastic leukemia cell line MOLT-4, Burkitt's lymphoma cell line Raji, colon cancer cell line SW480, and melanoma line G361.