JAK2 and myeloproliferative disorder: At the same time, it was found that the rs2736100 SNP, located in the second intron of the telomerase reverse transcriptase (TERT) gene, had a different allele frequency in familial MPN compared to sporadic cases [27] and exhibited a strong cancer predisposition effect in all MPN subtypes, regardless of the JAK2 gene mutations occurrence [23,32].