http://www.bloodjournal.org/content/102/10/3465?sso-checked=true

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0045592

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2894651/ (Links to an external site.)

http://www.jimmunol.org/content/164/11/5545.short (Links to an external site.)

http://www.theatlantic.com/health/archive/2014/10/your-babys-leftover-dna-is-making-you-stronger/381140/ (Links to an external site.)