32D cells containing EPO-R(W282R) or EPO-R(YF) do not proliferate in response to EPO. (•) MTT assay of 32D clones containing wild-type EPO-R; (○) EPO-R(1-373); (▵) EPO-R(W282R); and (□) EPO-R(YF). Data presented are from a single representative clone of each.