passages.id: split_6_test_853_passage
passages.type: progene_text
passages.text: A G22V mutant of M-Ras was constitutively active and its expression in an interleukin-3 ( IL-3 ) - dependent mast cell / megakaryocyte cell line resulted in increased survival in the absence of IL-3 , increased growth in IL-4 , and , at high expression levels , in factor - independent growth .