Analysis of μ chain glycoform expression in CLL cells after treatment with anti-μ. (A) Surface proteins were purified from 7 CLL samples treated in vitro with anti-μ (+) or isotype control (−) for 24 hours; μ chains were analyzed by immunoblotting. The immature form (◁) and the mature form (◀) of μ chain are indicated. (B) The graph shows the glycoform ratios in anti-μ–treated (+) or isotype control–treated (−) CLL samples measured after 24 hours of incubation in vitro. The difference between ratios between + or − treatments is statistically significant (t test, 2-tailed, paired, 99% CI).