TFAP4 and lymphoma: Since ~25% of lymphomas that spontaneously develop in Eμ-MYC transgenic mice show defects in the TRP53 pathway, we examined the sgTfap4/Eμ-MYC/Cas9 lymphomas, in which TFAP4 protein was absent, for abnormalities in the TRP53 pathway and compared them to the sgControl/Eμ-MYC/Cas9 lymphomas (Fig. 2A).