As for the research conducted by the four authors in the years immediately following the publication of "Sickle Cell Anemia,
a Molecular Disease", Itano, Singer and Wells continued on the same vein by analyzing abnormal hemoglobin and its synthesis;
whereas Pauling returned to structural chemistry, particularly the structures of proteins. Itano continued searching for abnormal
hemoglobins in vivo and successfully found three other abnormal hemoglobins within the next five years. He collaborated with James V. Neel for
one of these discoveries. Wells and Itano returned to the ratio issue and tried to determine the range of difference in the
ratios of sickle cell and normal hemoglobin in people with sickle cell trait. In addition, they analyzed whether the personal
differences depended on any of the following factors: effect of time (i.e. Does an individual's ratio change over time or
remain relatively constant?), sex, age, environment, diet, and heredity. Of all the factors they tested, Wells and Itano decided
that only heredity might explain the range. In addition to his work with Itano, Wells collaborated with two other researchers
from the Caltech chemistry department, Senior Research Fellow Walter A. Schroeder and Lois M. Kay to examine the amino acid sequences of sickle cell anemia and normal hemoglobin. In the mid-1950s to the
early 1960s, Itano and Singer investigated genetic factors of diseases caused by abnormal hemoglobin by focusing on the synthesis
of polypeptide chains in normal and abnormal hemoglobin.
As a result of the powerful work conducted on sickle cell anemia, more people at Caltech began to investigate normal and abnormal
hemoglobins, but they were not alone in this endeavor. The 1950s saw an extensive growth in laboratory studies of hemoglobin
and hemoglobinopathies. Additionally, genetic research boomed during this decade as a result of work on deoxyribonucleic acid
(DNA), especially after James Watson and Francis Crick elucidated the structure of DNA in 1953.