It is also noteworthy that a conserved LXCXE motif (thought to be involved in interactions with the pRb family of tumor suppressor proteins and suppression of innate antiviral immunity [31]) is located on the shared sT/LT leader sequence in the Avi and bandicoot viruses, whereas the LXCXE motif is instead located in the second exon of LT in Ortho and Almi species. This evidence concerns the gene RB1 and neoplasm.