“…14,16,24 In rodents, maternal ingestion of antiproliferative chemotherapy agents from embryonic day 10 to 12 (comparable to weeks 5-6 in humans) led to radial deficiencies and digital abnormalities. 25,26 Furthermore, treatment with busulfan, an antiproliferative chemotherapy agent, causes increased apoptosis, disruption in AER morphology, loss of AER-related Fgf8 expression, and reduced bone morphogenetic protein 4 expression. 27,28 Together, these findings suggest that RLD results from fetal insults that disrupt cell proliferation and reduce limb bud volume.…”