passages.id: split_8_test_1090_passage
passages.type: progene_text
passages.text: Using size - exclusion HPLC , ELISA , and CTLL-2 cell proliferation assays , we observed that the presence of 7G7 / B6 led to formation of complexes with sIL-2Ralpha and increased the serum levels of IL-2 more than 3 - to 40 - fold those of groups receiving IL-2 alone , sIL-2Ralpha , or hTac .