dephosporylation and phosphorylation (adding or removing a phosphate acts as an on/off switch; for some proteins its "on" others "off" and vice versa.... It's like a cascade of events, usually another protein known as a kinase would add the phosphate group, one the phosphate is added, the complex would work to stimulate something else (could be transcriptional changes, apoptosis, etc....) somewhere else along the cascade/pathway)
From what I gather, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4381966/, it appears that if this protein is phosphorylated, it is inhibited. Dephosphorylated,