IL1B and Friedreich ataxia: These early studies were conductedin vitro, but more recent work has unambiguously confirmed that murine FA stem cells are uniquely vulnerable to inflammatory stresses of many different kinds108,123 and that, in one informative model, blocking the function of the inflammatory cytokine interleukin 1 beta (IL-1β) (a suppressor of FA HSC proliferationin vitro)130 prevented marrow failure123.