KIF5B and medullary thyroid gland carcinoma: Additionally, SY-5007 exhibited potent anti-proliferative activity in the low nanomolar range across a variety of RET-fusion or mutant-driven cell lines, including TT cells (a human MTC cell line with RETC634W mutation), HEK293T-KIF5B-RETWT/ V804M/ M918T cells, Baf3-KIF5B-RETWT/ V804M/ M918T cells and Baf3-CCDC6-RETWT/ V804M/ M918T cells, while demonstrating minimal impact on the proliferation of normal cells (NIH-3T3) (Supplementary Table 2).