Clone m01

PBSTDS lysis buffer with the presence of protease cocktail inhibitor (Roche Diagnostics, Bazel, Switzerland) was used to extract total cell lysates. In total, 20% of 5 × SDS-loading buffer was added into 80% of cell lysates, then resolved by 10% SDS–PAGE gel and blotted onto PVDF membranes (pore size 0.45 μm, Millipore, Billierica, MA, USA). The primary antibodies anti-HOXB9 mouse monoclonal antibody (1 : 1000 dilution; Clone M01, Abnova, Taipei, Taiwan), anti-HOXB9 rabbit polyclonal antibody (1 : 1000 dilution; Santa Cruz, Dallas, TX, USA) anti-claudin-1, claudin-7, mouse monoclonal antibody (1 : 1000 dilution; Millipore, USA), anti-E-cadherin rabbit monoclonal antibody (1 : 1000 dilution; Epitomics, Burlingame, CA, USA), anti-Flag-monoclonal antibody (1 : 10 000 dilution; Clone M2, Sigma) and occludin monoclonal antibody (1 : 1000 dilution; Sigma) were incubated with the membranes separately under rotation. After thorough washing, membranes were further incubated with corresponding secondary antibodies recognising either rabbit or mouse Ig (Jackson Laboratories, Bar Harbor, ME, USA). Finally, the bands were visualised by the enhanced chemoluminescence (Pierce, Appleton, WI, USA).

Immunoprecipitation and immunoblotting experiments were performed as previously described.^{34 (link)} Antibodies against HA (1:2000; clone C29F4, cat # 3724S), β-actin (1:5000; clone 13E5, cat # 4970S), H3 (1:4000; clone 1B1B2, cat # 14269S) and RAD23A (1:1000; clone D7U7Z, cat # 24555) were purchased from Cell Signaling Technology, as was a non-specific isotype control IgG (clone DA1E, cat # 3900S). The FLAG antibody was from Sigma-Aldrich (1:4000; clone M2, cat # F1804). The Pol ι antibody was from Abnova (1:1000; clone M01, cat # H00011201-M01). Primary antibodies were detected with fluorescent secondary antibodies, and immunoblots quantified, as described previously.^{34 (link)} For the microarray, the Pol ι antibody was detected with an Alexa Fluor 647-conjugated goat anti-mouse secondary antibody (Thermo Fisher Scientific cat #A-21240).