JAK2 and myeloproliferative disorder: In addition, the abundance of JAK2 in familial MPN washigher than that in sporadic MPN (Figs. 6B, S5), suggesting an attenuated inhibitory effect of the CHST15 mutant on JAK2. The interaction between CHST15 and JAK2 was also confirmed by the acquisition of fluorescence images using a confocal laser scanning microscope, showing that JAK2 was mainly distributed on the plasma membrane and in the cytosol and nucleus, while CHST15 was mainly located onthe plasma membrane and in the cytosol.