The emergence of these AITL‐like tumours in Trp53ER/ER;Vav1ΔC/ΔC mice requires long latency times, since we could not detect any significant alteration in the overall numbers of T cells (Fig. 4A) and PD1+ CXCR5+ TFH populations (Fig. 4B,C) in 2‐ and 6‐month‐old Trp53ER/ER;Vav1ΔC/ΔC mice. Here, PDCD1 is linked to neoplasm.