Nelson et al. performed microarray analyses of skin biopsies from acne patients treated with isotretinoin for 1 week and cultured human sebaceous gland cells (SEB-1 sebocytes) incubated with isotretinoin for 72 hours and found that lipocalin 2 is the most highly upregulated gene induced by isotretinoin, which mediates the apoptosis of sebaceous glands of acne patients [8]. This evidence concerns the gene LCN2 and acne.