JAK2 and hepatocellular carcinoma: First, the mRNA expressions of JAK2 and STAT3 and the protein levels of JAK2/p-JAK2 and STAT3/p-STAT3 in HCC cells were detected after FAM99A overexpression (Figures 4A, B).The overexpression of FAM99A was found to cause no obvious changes in the mRNA levels of JAK2 and STAT3 in HCC cells compared with the control groups.