Kinase, in vitro: 

An enzyme-substrate reaction that occurs in non-living experimental conditions such as a test tube. For example, a purified enzyme is reacted with a substrate protein or mixture of proteins or peptides.

CDK5 S40-p , T121-p , S163-p
 Putative in vivo kinases: 

An enzyme-substrate reaction that occurs within living cells; includes cultured cells, ex vivo samples, and intact organisms. In the case of kinases, the large number of protein kinases in intact cells makes exact identification of the responsible kinase challenging.

CDK2 S40-p , T121-p , S151-p , S163-p
CDK5 S40-p , T121-p , S163-p
Phosphatases, in vitro:
PPP1CA S40-p
PPP2CA S40-p , S151-p
Putative upstream phosphatases:
PPP2CA S151-p
PTP4A3 T32-p , S36-p , S40-p , T121-p , S151-p , S163-p
Regulatory protein:
EGFR S138-p , S151-p
anti-CD3 S151-p
CXCL12 S151-p
okadaic_acid S40-p