Fetal liver samples were obtained from the Human Fetal Tissue Repository at Albert Einstein College of Medicine, Bronx, NY, and from Advanced Biosciences Resources, Alameda, CA.
And guess who's behind this research (scroll to the bottom of the same document):
Acknowledgments The authors thank the Regeneron Pharmaceuticals' Velocigene team for generating human IL-6 knock-in mice; J. Alderman for managerial support; C. Weibel, E. Henchey, and P. Ranney for technical assistance; and C. Lieber for manuscript submission...... This study was supported by the Bill and Melinda Gates Foundation, the National Institutes of Health, National Cancer Institute (R01 CA156689) (R.A.F.), and the American Diabetes Association Research Foundation Mentorship Fellowship (H.Y.). R.A.F. is an Investigator of the Howard Hughes Medical Institute.
https://www.sciencedirect.com/science/article/pii/S0006497120336673
Thanks for the link. Seems fairly damning.