Given the task definition and input, reply with output. In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

 Neither full - length isoform alters growth of a myeloid cell line under nondifferentiating conditions , but the proximal isoform selectively delays mitotic arrest of the cell line under differentiating conditions , resulting in the generation of greater numbers of neutrophils .

proximal isoform