Apart for being non-cancerous these fibroblast have limited growth cycle of 40 to 50 passages.Moreover, some used epithelial derived normal cells while some used lung derived fibroblast, to test the selectivity and anti-cancer potentail of a drug. Is there any other rational of using MRC-5/WI-38 or fibroblast and not epithelai cells.

Thank you in advance and looking forward for some detail responses and reasoning for using these cells.