Western blot analysis of AcH3 and AcH4 in NB4 and R4 cells treated with tRA combined with HMBA or NaB.

The cells were treated with 10⁻⁷ μM tRA, 2 mM HMBA, and 0.5 mM NaB, alone or in combination as labeled, for 3 days. AcH3 and AcH4 were isolated and detected as described in “Materials and methods.”