I thank Marisa Marques, MD, Professor, Pathology Department, University of Alabama at Birmingham, for introducing me to a concise review article, Palla R, Peyvandi F, Shapiro AD. Rare bleeding disorders” diagnosis and treatment. Blood 2015;125:2052–61, available free from The American Society of Hematology. The article answers many questions about the rare deficiencies of factors II, V, VII, X, XI, V/VIII combination, XIII, vitamin K-dependent coagulation factors, and fibrinogen. Enjoy!