FANCM is not essential for the assembly of the FA core complex. (A) Parental HeLa cells (lane 1) and Flag-FANCL HeLa cells (lanes 2,3) transfected with indicated siRNAs for 72 hours were incubated with MMC (50 ng/mL for 17 hours) and harvested and immunoblotted for the indicted protein. (B) Cells treated as in panel A were extracted with 300 mM NaCl-CSK buffer and immunoprecipitated with FLAG-M2 agarose beads. The precipitates (lanes 1-3) and input (lanes 4-6) were immunoblotted for the indicated proteins.