(A). RIP analysis of pri-let-7a1 and Flag-TruB1 from HEK-293FT cells. RNA was extracted from IP material and analyzed by qRT-PCR. HEK-293FT cells were infected with lentiviruses encoding tetracycline-inducible expression of TruB1, mt1, mt2, or GFP and treated with doxycycline. Error bars show SD; n=3. Significance was assessed using 2‐tailed Student's t‐test, < 0.05*. 