Wiktor Stein is considered one of the founders of Polish neurology after World War II (Fig. 1). He created the neurological clinic at the Mari Curie Skłodowska University (UMCS) of Lublin from scratch; using clinical experience gained at Lviv where Kazimierz Orzechowski (1878–1942) [1] also studied. In the scientific dimension, Stein was fascinated by the possibility of identifying centers involved in the process of regulating blood composition within the central nervous system. He was also the first to undertake research on the importance of leukocyte aggregation (leukergic) reactions in neurology. Those reactions were first discovered by Ludwik Fleck [2], who after World War II also worked at the same medical faculty in Lublin [3‐5]. Currently, the phenomenon of leukocyte aggregation has some significance in explaining the etiology of neurological complications in the course of inflammatory diseases [6]. What is more, it has also become a subject of research for its connections with trauma and stress [7]. In the 1950s and 1960s, Stein also conducted research, of great clinical significance, on inflammatory changes in the cerebrospinal fluid in the course of tuberculous meningitis. To his successors at the neurology clinic in Lublin, Stein instilled the passion for searching for a drug that could cure multiple sclerosis (MS).