The aim of this paper is to draw attention to an interesting semilinear parabolic equation that arose when describing the chaotic dynamics of a polymer molecule in a liquid. This equation is nonlocal in time and contains a term, called the interaction potential, that depends on the time-integral of the solution over the entire interval of solving the problem... In fact, one needs to know the "future" in order to determine the coefficient in this term, i.e., the causality principle is violated. The existence of a weak solution of the initial boundary value problem is proven. The interaction potential satisfies fairly general conditions and can have an arbitrary growth at infinity. The uniqueness of this solution is established with restrictions on the length of the considered time interval. (read more)