cells. In contrast to ATRA, all conjugates bearing amino acids with polar side chains showed no inhibitory effect on LNCaP cell proliferation, while conjugates with α-amino acids with lipophilic side chain, such as 7, or linear amino acids, such as 9, significantly decreased prostate cancer LNCaP cell number. Interestingly, while the effect of ATRA was RARα-dependent, the effect of its active analogues