Sentence examples for it has been difficult so far from inspiring English sources

However, it has been difficult so far to generate strong and consistent adhesion blocking antibody responses against most single-domain VAR2CSA immunogens.

However, it has been difficult so far to exploit this molecular tool to differentiate among species within the Diptera, particularly the economically important family Tephritidae [ 4].

So far, it has been difficult to grow replacement liver cells in the lab.

Indeed, it has been enormously difficult so far to transfer any promising advances in neuroscience into everyday clinics.

However, the design of selective pharmacological inhibitors of HSP70 has been difficult and only few have been described so far.

So far the transition has been difficult.

So far, though, finding the right price has been difficult.

So far, however, RNA-related drugs have been difficult to develop.

Due to the complexity of the disease, the search for specific CD susceptibility genes has been very difficult so far.

So far it has been a delight.

So far it has been smooth.