PABIR1 and T-cell acute lymphoblastic leukemia: Furthermore, the anti-FAM122A antibody-based IP assay also confirmed the interaction of endogenous FAM122A and PP2A-Aα, B55α, and Cα but not B56α proteins in 293T (Figure 2L) and Jurkat cells (Figure 2M), a human acute T cell leukemia cell line.