CLK2 and disease of the tendon: Knockdown of CLK2 promoted tenocyte differentiation by inhibiting the expression of tenocyte catabolic enzymes, indicating that targeting CLK2 may play a protective role against tendinopathy.69 SM04755 was identified as a potent inhibitor of CLK2 and DYRK1A with an IC50 of 5.0 nM and 3.5 nM, respectively.