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.
Q: Moreover , we show that ectopic expression of the E2A protein E12 in this macrophage line results in the induction of many B lineage genes , including EBF , IL7Ralpha , lambda5 , and Rag - 1 , and the ability to induce kappa light chain in response to mitogen .
A:
kappa light chain