MYC and breast cancer: In order to decipher the role of JAK2 inhibition-mediated PDGFRβ accumulation in breast cancer cells, we ectopically expressed plasmids encoding for transcription factors MYC [38] and STAT3 [39] that are known to regulate PDGFRβ levels as well as mJAK2, an upstream regulator of JAK/STAT signaling in SUM159PT cells for 24 or 72 h.