Cells that make up our bodies exhibit diverse morphologies depending on their functions. A key factor in determining cell shape is the microtubule network, along with motor proteins such as kinesin and dynein, which utilize microtubules as tracks. Among various cell types, neurons are particularly specialized in both shape and function, making them a suitable model for studying the mechanisms of cellular morphogenesis. Using neurons as our primary model, we have investigated how microtubules and motor proteins contribute to shaping cells. Through this research, we have also gained insights into the mechanisms underlying diseases such as amyotrophic lateral sclerosis (ALS) and hereditary spastic paraplegia.