One of the translocation chromosomes is a small marker chromosome, comprised of the centromere and proximal end of Chr 17 (~ 9.5 Mb) and the distal end of mouse Chr 16 (~ 34Mb). (jax.org)
Only the proximal ends (area of interest with pathology) were scanned, as full scans were not possible due to the size limitations of the X-Tek system. (rsos.royalsocietypublishing.org)
It's in the outermost layer of muscle, lying superficial to the proximal end of the biceps brachii short head, pectoralis minor and coracobrachialis. (kingofthegym.com)