This state involves the abnormal differentiation of CD4+ T helper type 2 cells and the overproduction of immunoglobulin E.[15] Earlier studies have suggested that children with atopy are more likely to get infected with Mycoplasma, and such infections can cause a significant increase in immunoglobulin E levels – especially during the acute phase of the infection or when the child is in an allergic state. The gene discussed is CD4; the disease is infection.