PTPA and colorectal carcinoma: For instance, E7 can bind to cyclins A, D and E in the absence of pRb [168, 169], and inhibits the dephosphorylation of protein kinase B, which is carried out by protein phosphatase 2A (PP2A), thus maintaining the activity of the phosphoinositide‐3‐kinase (PI3K) signalling pathway, which is one of the important signalling axes in CRC [170, 171].