Human iPS lines containing the JAK2-V617F mutation from PB CD34⁺ cells of 2 MPD patients. (A) Immunostaining of different colonies from a representative iPS line (clone 8) derived from MPD183 shows the expression of undifferentiated cell markers TRA-1-60, SSEA4, and NANOG. (B) A pluripotency test for the iPS clone 8 from MPD183 (iMPD183.C8) after EB formation (day 10) as we did for human ES cells and other (normal) iPS cells, showing that JAK2-V617F iPS cells can also differentiate into various cell types expressing markers of 3 embryonic germ layers. Similar results were obtained from the iPS clone 3 of the second MPD patient (iMPD562.C3) before and after EB-mediated differentiation, as shown in supplemental Figure 4. (C) In vivo differentiation potential after teratoma formation from MPD183-derived iPS cells. Hematoxylin and eosin staining of various slides after sectioning shows various tissues from the 3 embryonic germ layers: gut epithelium (endoderm), cartilage (mesoderm), and glycogenated epithelium (ectoderm). (D-E) Expanded iPS lines from the 2 female MPD patients (D: MPD183; E: MPD562) retained a normal karyotype (46,XX), after 10 and 11 passages, respectively. Scale bar represents 200 μm.