  In this note, we try to understand the recent development on the
Waring-Goldbach problem involving cubes of primes. Especially, we want to
determine whether integers that are either primes, squares of primes, cubes of
primes, or a cube of an even number can be written as the sum of four cubes of
primes. Meanwhile, we raise some problems that may deepen our understanding of
the problem about the sum of four cubes of primes. Moreover, some examples
suggest that almost all the cubes of integers can be written as the sum of
cubes of four integers.
