PARP1-binding site offers better electrostatic surface complementarity for niraparib and veliparib recognition than TNKS1-binding site. Electrostatic surface representation (blue denotes positive and red negative electrostatic surface) of (A) PARP1-niraparib, (B) TNKS1-niraparib, (C) PARP1-veliparib, and (D) TNKS1–veliparib complexes. PARP1, poly(ADP-ribosyl) polymerase 1; TNKS1, tankyrase1.