Updated publication reference for PubMed record(s): 35192416. The New Kinase Family 3 (NKF3) of pseudokinases comprises PEAK1 and PEAK2 as well as the recently-identified PEAK3. PEAK1/2 play fundamental roles in regulating tyrosine kinase signal output and oncogenesis, while PEAK3 remains poorly-characterized. Here we demonstrate that PEAK3 undergoes homotypic association as well as heterotypic interaction with PEAK1/2. PEAK3 also recruits ASAP1/2, Grb2, CrkII, Cbl and PYK2 with effector recruitment being dependent on PEAK3 dimerization. PEAK3 tyrosine phosphorylation on Y24 is also dependent on dimerization as well as Src family kinase activity, and interestingly, is decreased via PTPN12 in response to EGF treatment. Both phosphorylation of Y24 and an intact N-terminal SH3 binding motif are required for optimal binding of Grb2, CrkII and ASAP1. Overexpression of PEAK3 in MDA-MB-231 breast cancer cells enhanced cell elongation and cell motility, while knockdown of endogenous PEAK3 decreased cell migration. In addition, overexpression of PEAK3 in PEAK1/2 compound knock-out MCF-10A breast epithelial cells enhanced acinar growth and invasion in 3D culture, with the latter phenotype dependent on PEAK3 tyrosine phosphorylation and ASAP1 binding. These findings characterize PEAK3 as an integral member of NKF3 with scaffolding roles that promote cell proliferation, migration and invasion.