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.

 Overall , the phenotype observed in XHM - ED patients shows that the putative zinc - finger domain of NEMO has a regulatory function and demonstrates the definite requirement of CD40 - mediated NF - kappaB activation for B cell immunoglobulin class - switching .

NF - kappaB