Putative regulatory subunit of protein phosphatase 6 (PP6) that may be involved in the recognition of phosphoprotein substrates. Involved in the PP6-mediated dephosphorylation of NFKBIE opposing its degradation in response to TNF-alpha. Selectively inhibits the phosphatase activity of PPP1C. Targets PPP1C to modulate HNRPK phosphorylation (By similarity). Protein phosphatase 6 (PP6) holoenzyme is proposed to be a heterotrimeric complex formed by the catalytic subunit, a SAPS domain-containing subunit (PP6R) and an ankyrin repeat-domain containing regulatory subunit (ARS). Interacts with PPP1C and HNRPK. Interacts with PPP6C, PPP6R1 and PPP6R3 (By similarity). Seems to be excluded from nucleoli. Widely expressed (at protein level).