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(Figure 1). I still clearly remember that I was in seventh heaven when I saw my printed paper. As my research was started with megakaryocytes, I wanted to stick to this research theme in the future. However, the material used for the study on mega-karyocytes is human bone marrow blood that is difficult to obtain, and the number of formed mega-karyocyte colonies varied between individuals and caused variability of the data; therefore, I felt the difficulty of the experiment. Not only that but also I was too impatient to wait for colony formation for two weeks. Therefore, I decided to use megakaryo-cytic leukemia cell lines in the experiment, which were available as a material every time I needed, and to change my direction from the conventional research where bone marrow blood was used.I am satisfied with its publication in British Journal Haematology (the right photo). At that time, the acceptance was notified by a letter (the left photo).topoiesis in essential thrombocythemia, my life work. After that, I had an opportunity to receive direct guidance for the research from Dr. Toshio Suda (currently a professor at National University of Singapore), but the formation of megakaryocyte colonies in humans was still considerably difficult, and it was hardly conducted in Japan. A factor that stimulates human megakaryocyte colony, thrombo-poietin, was not yet identified at that time. There-fore, the culture supernatant of human lympho-cytes stimulated with phytohemagglutinin (PHA) (PHA-stimulated lymphocyte conditioned medium: PHA-LCM) was used for the formation of human megakaryocyte colony, but the quality of PHA-LCM greatly affected the formation of human mega-karyocyte colony. I asked approximately 20 students, doctors, or nurses to give me their blood, to collect mononuclear cells, and then prepared PHA-LCM. Then, I used the bone-marrow blood donated by healthy volunteers (medical students at Jichi Medical University), and examined the PHA-LCM prepared from whose blood was most capable of forming megakaryocyte colonies. As a result, surprisingly, the PHA-LCM made from my own peripheral blood was most capable of forming megakaryocyte colonies. It was a fortunate discovery. Since then, I’ve used my blood to prepare PHA-LCM when necessary without having to worry about anyone else. My paper on megakaryocyte coloniza-tion in essential thrombocythemia (ET) was published in “British Journal of Haematology”1) that I had admired during my youth, and became my first paper to commemorate in my basic research Figure 1　My first research paper after assigned to be a physicianThe first cell line used for research was CMK, a cell line with the nature of megakaryocytes. I received it from Dr. Takeyuki Sato at Chiba Univer-sity and started a new research. Stimulation of the CMK cell line with a phorbol ester (also known as TPA or PMA) resulted in differentiation into mature megakaryocytes. One day, I happened to see the culture supernatant oddly become yellowish. I do not know why (not remember), but I tried sprinkling the culture supernatant on the original CMK cells. Surprisingly, the proliferation of the CMK cells was markedly enhanced. From the beginning, I thought that its activity was similar to GM-CSF. After I asked a laboratory to examine 409Success comes from failure─Encounter with UT-7─