The relationship between KL-6 and Hb is seldom reported; a recent study showed that KL-6 and Hb can both be used to assess bone marrow fibrosis (21), but the interaction between KL-6 and Hb is still unknown, and the mechanism through which Hb is correlated to KL-6 needs further investigation. This evidence concerns the gene MUC1 and primary myelofibrosis.